low light
ipy2006
best DSLR for this purpose?
Thanks,
Yip
ASAAR
> I have to shoot action photos in low light conditions. What is the
> best DSLR for this purpose?
It's never just a matter of getting the best DSLR for the purpose.
It's a DSLR body + lens combination that must be considered, as well
as the low light level and specific types of actions you need to
shoot. Some combinations will be so demanding that there may not be
a suitable solution. Others may be so easy that almost any DSLR
will do. If you can determine the minimum gear that will suffice,
you can save a lot of money buying a body and lens(es). If you
don't know but have enough money to burn, you could start with a
Canon 5D and see if that and a typical "kit" lens gets you what you
need. If not, you might need to spend about $1000 or even several
thousand dollars getting a better lens if the kit lens proves
inadequate. If your sports shooting demands long bursts of shots at
very high frame rates, you might need to get a much more expensive
body than the 5D, ie, one of the "pro" bodies from Canon or Nikon.
You gave no information at all as to the kind of action photos
you'll be shooting or in what kind of low light levels. If you can
tell us what they are, you might get some concrete examples of what
kind of DSLR will meet your needs. Which brings up another point.
You really want to know what kind of cameras will be suitable. You
don't want to ask what the BEST DSLR is, because the "best" for one
person won't be the best for another, and the absolute "best" for
*you* might be $8,000 above your budget, whereas a $1,200 camera
with kit lens might do everything you're looking for, and would be
good enough. Care to share which camera(s) you're currently using,
if any?
tomm42
I'd look at a Canon 30D, about the best for a reason able price, the
Canon 5D is better but 3X (approx) the price. Canons seem to have a
heavier in camera noise reduction than the cameras with a Sony sensor.
Remember you won't get by with a kit lens here. If you are in school
gyms, swimming pools etc you will neeed at least an f2.8 lens. A
70-200 f2.8 pushes $2K. If you buy single focal length lenses 85 -
135mm should cover what you need, just look at lenses that are f1.4-
f2.8, price escalate dramaticly after 135mm. Some claim they get by
with a fast 50mm, doesn't seem long enough for me. An 85 f1.8 or a 135
f2 should be good lenses to look at, depending on the distance of the
action. Just calculate what f-stop and ISO can get you to a shutter
speed of at least 1/250 of a second.
Vibration reduction will be of minimal usefulness you should be at
shutter speeds that don't need it and the blur will come from the
action.
Tom
ipy2006
Here are some scenarios,
Indoor shooting of people talking with hand gestures, people walking
or pacing in the room, kids playing, women cooking in kitchen, or
groups of people in meeting rooms etc. Sometimes I don't have the
ability to use lights, I need to depend on flash and high brightness
setting. Currently, I am using a Sony Digital Camera, Cyber-shot, DSC-
H2. My budget is $1000 and at the most $1500.
I read some review that Canon Eos Digital Rebel xTi DSLR is good low
lighting. Nikon D80 was good but the article said more as a available-
light camera.
Please comment.
Thanks,
yip
bworthey
"ipy2006" <ipya...@gmail.com> wrote in message
news:1173274977.0...@h3g2000cwc.googlegroups.com...
>
> Here are some scenarios,
> Indoor shooting of people talking with hand gestures, people walking
> or pacing in the room, kids playing, women cooking in kitchen, or
> groups of people in meeting rooms etc. Sometimes I don't have the
> ability to use lights, I need to depend on flash and high brightness
> setting. Currently, I am using a Sony Digital Camera, Cyber-shot, DSC-
> H2. My budget is $1000 and at the most $1500.
>
> I read some review that Canon Eos Digital Rebel xTi DSLR is good low
> lighting. Nikon D80 was good but the article said more as a available-
> light camera.
>
> Please comment.
From what it sounds like with the situations you described there will be
some sort of lighting source, not like the people are in complete darkness
or anything or not lights on in the house/room at all. I have teh Canon XTI
and I have been suprised wtih the situations where I have not had to use the
flash at all, with just appropriate adjustment with shutter, aperture, and
white balance I have gotten some really good pictures.
B-Worthey
Roger N. Clark (change username to rnclark)
> On Mar 7, 7:03 am, "ipy2006" <ipyasa...@gmail.com> wrote:
>> I have to shoot action photos in low light conditions. What is the
>> best DSLR for this purpose?
>> Thanks,
>> Yip
>
>
> I'd look at a Canon 30D, about the best for a reason able price, the
> Canon 5D is better but 3X (approx) the price. Canons seem to have a
> heavier in camera noise reduction than the cameras with a Sony sensor.
Not quite. Canon sensors have inherently low noise at low signal
levels. Noise reduction implies some method of reducing noise,
and that can only be done by averaging pixels to reduce
spatial resolution. One can do that in software in post processing.
It helps to have a good low noise/high signal system to begin with.
See:
Digital Cameras: Does Pixel Size Matter?
Factors in Choosing a Digital Camera
http://www.clarkvision.com/imagedetail/does.pixel.size.matter
Digital Camera Sensor Performance Summary
http://www.clarkvision.com/imagedetail/digital.sensor.performance.summary
For the OP: choose a camera with the largest pixels and the lowest
read noise. The two relevant plots on the digital.sensor.performance.summary
web page are Figure 3 (lower on the plot is better), Figure 6 (higher
on the plot is better) and Figure 7 (higher = better).
> Remember you won't get by with a kit lens here. If you are in school
> gyms, swimming pools etc you will neeed at least an f2.8 lens. A
> 70-200 f2.8 pushes $2K. If you buy single focal length lenses 85 -
> 135mm should cover what you need, just look at lenses that are f1.4-
> f2.8, price escalate dramaticly after 135mm. Some claim they get by
> with a fast 50mm, doesn't seem long enough for me. An 85 f1.8 or a 135
> f2 should be good lenses to look at, depending on the distance of the
> action. Just calculate what f-stop and ISO can get you to a shutter
> speed of at least 1/250 of a second.
> Vibration reduction will be of minimal usefulness you should be at
> shutter speeds that don't need it and the blur will come from the
> action.
For indoor action shots, a 50mm f/1.8 lens is very low cost (about %70)
and very high performance. Remember, on a 1.6x crop camera,
50 mm is like 80 mm on a full frame camera regarding full field
of view.
Roger
Roger N. Clark (change username to rnclark)
> Here are some scenarios,
> Indoor shooting of people talking with hand gestures, people walking
> or pacing in the room, kids playing, women cooking in kitchen, or
> groups of people in meeting rooms etc. Sometimes I don't have the
> ability to use lights, I need to depend on flash and high brightness
> setting. Currently, I am using a Sony Digital Camera, Cyber-shot, DSC-
> H2. My budget is $1000 and at the most $1500.
What, you don't take pictures of men cooking in the kitchen?
>
> I read some review that Canon Eos Digital Rebel xTi DSLR is good low
> lighting. Nikon D80 was good but the article said more as a available-
> light camera.
>
> Please comment.
The rebel xti (400D) has smaller pixels than other rebel cameras,
5.7 microns) (and smaller than many other DSLRs). I don't have
data on the xti, but can see on Figure 6 at
http://www.clarkvision.com/imagedetail/digital.sensor.performance.summary
that plotting at 5.7 microns in the gray band, the
performance would probably be below most other DSLRs on the plot.
(If you can't see the gray band on the plot, your monitor
is set too bright/too high contrast.)
Roger
Skip
mkIII, it shoots 10 fps, has a "silent mode," an ISO range up to3200
expandable to 6400. That being said, a appropriate lens is critical to the
equation. Depending on what the subject is, a 70-200 f2.8 zoom or a fixed
focal length lens like the 100 f2, 85 f1.8 or 85 f1.2 could be excellent
choices. Notice, when you say "best," without saying what you're budget is,
the best is expensive, the body will probably be in the $4000+ range, the
70-200 f2.8 is about $1600, and the 85 f1.2 is about $1200.
--
Skip Middleton
www.shadowcatcherimagery.com
www.pbase.com/skipm
DeanB
<usern...@qwest.net> wrote:
> tomm42 wrote:
> > On Mar 7, 7:03 am, "ipy2006" <ipyasa...@gmail.com> wrote:
> >> I have to shoot action photos in low light conditions. What is the
> >> best DSLR for this purpose?
> >> Thanks,
> >> Yip
>
> > I'd look at a Canon 30D, about the best for a reason able price, the
> > Canon 5D is better but 3X (approx) the price. Canons seem to have a
> > heavier in camera noise reduction than the cameras with a Sony sensor.
>
> Not quite. Canon sensors have inherently low noise at low signal
> levels. Noise reduction implies some method of reducing noise,
> and that can only be done by averaging pixels to reduce
> spatial resolution. One can do that in software in post processing.
> It helps to have a good low noise/high signal system to begin with.
>
> See:
> Digital Cameras: Does Pixel Size Matter?
> Factors in Choosing a Digital Camera
> http://www.clarkvision.com/imagedetail/does.pixel.size.matter
>
> Digital Camera Sensor Performance Summary
>
> For the OP: choose a camera with the largest pixels and the lowest
> read noise. The two relevant plots on the digital.sensor.performance.summary
> web page are Figure 3 (lower on the plot is better), Figure 6 (higher
> on the plot is better) and Figure 7 (higher = better).
>
> > Remember you won't get by with a kit lens here. If you are in school
> > gyms, swimming pools etc you will neeed at least an f2.8 lens. A
> > 70-200 f2.8 pushes $2K. If you buy single focal length lenses 85 -
> > 135mm should cover what you need, just look at lenses that are f1.4-
> > f2.8, price escalate dramaticly after 135mm. Some claim they get by
> > with a fast 50mm, doesn't seem long enough for me. An 85 f1.8 or a 135
> > f2 should be good lenses to look at, depending on the distance of the
> > action. Just calculate what f-stop and ISO can get you to a shutter
> > speed of at least 1/250 of a second.
> > Vibration reduction will be of minimal usefulness you should be at
> > shutter speeds that don't need it and the blur will come from the
> > action.
>
> For indoor action shots, a 50mm f/1.8 lens is very low cost (about %70)
> and very high performance. Remember, on a 1.6x crop camera,
> 50 mm is like 80 mm on a full frame camera regarding full field
> of view.
>
> Roger
This (1.2) would be a lens to save up for in your situation:
http://www.usa.canon.com/consumer/controller?act=ModelDetailAct&fcategoryid=152&modelid=12926
But the 1.4's are about $900 to $1000.
ipy2006
>
> But the 1.4's are about $900 to $1000.- Hide quoted text -
>
> - Show quoted text -
Thank you all for your feedback.
Yip
imapho...@yahoo.com
I've had about a year with DSLRs after a few years with higher end
digitals. I made the transition due to similar circumstances - the
family and friends refused to stay still in bright light while i was
awake.
Here's the best piece of advice I've been told by a coupl eof people
and experience is confirming this:
"It's all about the lenses"
Unlike a lot of consumer electronic devices where the base unit is
important rather than the peripherals, DSLRs aren't quite the same
way.
Lens end up being more important because:
1) The optics determine quality to a large extent. I didn't say all
or 99% or anything else is trivial. But the glass is a huge factor.
2) The lenses will outlive the body. Especially digital bodies where
technology changes and improves so rapidly. Even in the film age, the
investment ended up in lenses.
3) Lenses largely determine how much light is needed for a good shot.
4) You can always start with a lower level body and a great set of
lenses and get great pics in tough lighting situations immediately.
Great body but mediocre kit lenses will leave you in the same
situation as with many point-and-shoot cameras today - just can't do
it. Kit lenses are rarely good enough to use in low light situations.
My recommendations, to be taken as a rough and still a bit not fully
informed opinion... I have a Canon 400D so I'm only going to talk
about things I have *some* idea about. Again, you are going to have
to do your own research despite what any of us says.
Lenses:
Tamron SP AF17-50mm F/2.8 XR Di-II LD Aspherical - for close to normal
indoor shots, and outdoor shots within talking distance. And the
everyday, always on default lens.
Canon EF 85mm f/1.2L II USM - the classic, very good 3-4x-ish
telephoto lens for low light situations, from portrait to kid sports
(after the first two and the body, we have:) Canon EF 70 - 300mm
f4.5-5.6 DO IS USM - for extended telephoto shots
Body:
Start with a good used 300D or 350D. The 350D would be a good choice
as the 400D is more or less 350D with a couple of extra near-
superfluous megapixels and a cleaning system (very nice but we're
trying to conserve dollars here for lenses and accessories).
Certainly a XTi (400D) is a good choice but I'm concerned about the
budgetary restraints you gave. Again, invest in lenses - you can swap
bodies out later. I've done one swap out from a used 300D to a new
XTi.
Don;t forget the key essentials.... flash (search for 430EX, vivitar
flash, sunpak flash), and a good tripod. there's another $200-400!
But with the flash, you can settle for using cheaper 3rd party items
at th beginning. But preferable to buy new.
And a travel case. $25-50.
Nikon is another good choice to Canon since they have a nice huge
selection of lenses to choose from - including 3rd parties. Perhaps
the Nikkoners can provide some detailed recommendations here.
Rutger
news:1173268980.6...@h3g2000cwc.googlegroups.com...
The one with the biggest sensor. And wit biggest i mean in millimetres, NOT
in megapixels. The bigger the sensor, the lower the noise, which will
certainly occur when shooting in low light.
Rutger
--
http://www.flickr.com/photos/zwaarddrager
ASAAR
> Here are some scenarios,
> Indoor shooting of people talking with hand gestures, people walking
> or pacing in the room, kids playing, women cooking in kitchen, or
> groups of people in meeting rooms etc. Sometimes I don't have the
> ability to use lights, I need to depend on flash and high brightness
> setting. Currently, I am using a Sony Digital Camera, Cyber-shot, DSC-
> H2. My budget is $1000 and at the most $1500.
>
> I read some review that Canon Eos Digital Rebel xTi DSLR is good low
> lighting. Nikon D80 was good but the article said more as a available-
> light camera.
>
> Please comment.
I have no idea what the review meant. I'd take referring to a
camera as "good low lighting" and "more as a available light camera"
to be the same thing, both seem to be praising the camera's low
(available) light ability. Both are good cameras, and well within
your budget, leaving enough room left over to get a good flash. But
the cameras that they replaced are probably better from a low light
standpoint, because these (Canon's 350D and Nikon's D50), using the
same size sensors, have fewer, larger pixels. This makes them able
to collect more light and for the same high ISO setting, produce
less "noise". Canon claims that despite having smaller pixels, the
400D is no noisier than the 350D, based on using better electronics,
but I'd guess that the difference is slight, and whatever difference
there is, the advantage would probably be to the 350D. I think that
the 350D and D50 do at least as well in low light and perhaps better
than their newer, more expensive siblings.
These older models are still available new, and you can get them
for many hundreds of dollars less than the current models. The
"kit" lenses for these cameras are usually something like 18mm-55mm
and are very inexpensive. These lenses would probably be well
suited for some of the slower activities you mentioned - women
cooking, people in a meeting room, maybe people walking and pacing,
etc. With the money saved by not going for the more expensive 400D
or D80, there's a slim chance that you *might* be able to afford a
longer, faster, and unfortunately heavier f/2.8 zoom, that would be
ideal for capturing fast moving pets, children playing, some sports
activities, etc. B&H has the D50 body in stock for $450 (new) and
$400 (used). The 350D is $488 (new). Nikon's recent "budget" DSLR,
the D40 is quite similar to the D50, and it's main limitation
wouldn't be a limitation for you. It won't autofocus with old Nikon
lenses. B&H has it for $570, and this includes Nikon's 18-55mm
f/3.5-5.6 kit lens. Add the same or a similar lens to the D50 or
350D and the price will be in the same ball park. This would leave
your budget with just under $1000 remaining. That could be put to
very good use if these lenses aren't suitable for collecting lots of
light. You'd be all set if a fixed length lens of about 50mm would
do, since an f/1.4 or f/1.8 lens is fairly inexpensive. If you need
a longer lens, then you'd want to look for one that has an f/2.8
aperture, but the prices for these rise rapidly. Longer f/2.8 zoom
lenses are probably well beyond your budget.
Paul Furman
> Here are some scenarios,
> Indoor shooting of people talking with hand gestures, people walking
> or pacing in the room, kids playing, women cooking in kitchen, or
> groups of people in meeting rooms etc. Sometimes I don't have the
> ability to use lights, I need to depend on flash and high brightness
> setting. Currently, I am using a Sony Digital Camera, Cyber-shot, DSC-
> H2. My budget is $1000 and at the most $1500.
>
> I read some review that Canon Eos Digital Rebel xTi DSLR is good low
> lighting. Nikon D80 was good but the article said more as a available-
> light camera.
>
> Please comment.
For that budget, a Nikon D50 or Canon XTI with a Sigma 30mm f/1.4 lens.
The fixed focal length gets you faster, wider aperture and that's the
appropriate normal focal length for home sized rooms indoor groups of
people.
ray
I should think the 'best' solution would be a film SLR with high speed
film. I don't think the practical ISO ranges available on DSLRs yet match
what is available with film.
Paul Furman
I think he will need a wider lens for groups of people in a kitchen
unless it's a huge kitchen. I initially only saw the $1000 budget but
with $1500 he could get a Nikon D50, Sigma 30mm f/1.4 and 18-70mm
lenses. I don't know the Canon options as well.
nospam
<r...@zianet.com> wrote:
> I should think the 'best' solution would be a film SLR with high speed
> film. I don't think the practical ISO ranges available on DSLRs yet match
> what is available with film.
digital is *much* better than film at high iso.
Tzortzakakis Dimitrios
? "ipy2006" <ipya...@gmail.com> ?????? ??? ??????
news:1173268980.6...@h3g2000cwc.googlegroups.com...
> I have to shoot action photos in low light conditions. What is the
> best DSLR for this purpose?
> Thanks,
Nikkor 50 mm 1.4 (either delta or T-Max).Now I use a P&S, and besides I was
a Nikon fan, canon cameras are generally very good.
--
Tzortzakakis Dimitrios
major in electrical engineering
mechanized infantry reservist
dimtzort AT otenet DOT gr
David Dyer-Bennet
> I have to shoot action photos in low light conditions. What is the
> best DSLR for this purpose?
Well, any of the Nikon or Canon offerings are going to be significantly
better than what you're using now (I've read ahead some).
On the other hand, many of the good choices blow your $1500 max budget
*before* buying a lens. By a factor of about 5, in some cases. At that
budget, anything remotely resembling the "best" the market currently has
to offer is completely off the radar. Some of the lenses you might
want to buy for this work blow your $1500 budget all by themselves.
Sounds like you're talking bright home / average office brightness
levels, rather than really low light levels. And people in normal life,
rather than high-speed sports and such.
I would suggest that you'll be best off with a bottom-end DSLR from
Canon or Nikon plus the best fast lenses you can fit into the budget.
Nothing slower than f/2.8 need apply. You want at least one at f/1.4 or
faster, probably either a 50mm or the Sigma 30mm. And you still won't
be able to get what you really need for $1500. You also need the good
flash, in Nikon the SB-800, I forget the Canon equivalent model. The
Nikon flash system is generally thought better than the Canon, the Canon
noise at high ISOs is generally thought lower than the Nikon in
comparable cameras. The Canon fast lenses seem to be cheaper, but on
Nikon you can get cheap manual focus fast lenses and still use them on
the DSLRs. It's all a bunch of tradeoffs.
But your $1500 just isn't going to cut it with anything other than
fairly blatantly compromised equipment.
David Dyer-Bennet
In my experience, this is massively wrong. High ISO is where digital
completely blows film away; there's no comparison. (I've been pushing
TRI-X since 1969, shooting the Konica 3200 color neg when it was
available, and oh *man* is digital better than any of that.)
Rutger
news:070320070812162004%nos...@nospam.invalid...
That is *very much* dependand by brand.
Rutger
--
http://www.flickr.com/photos/zwaarddrager
UC
None. You need light to do photography, you moron.
Floyd L. Davidson
Digital is significantly better at higher ISOs.
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) fl...@apaflo.com
Floyd L. Davidson
>I have to shoot action photos in low light conditions. What is the
>best DSLR for this purpose?
Either Canon or Nikon will do fine, as well as perhaps others.
The camera itself isn't really that important, compared to lense
selection. (I use Nikon equipment, so that is what I'll discuss
specifically, but the basic selection process would be the same
for any brand of camera.)
The trick is to figure out which lenses you actually *need*.
Consider that there are inexpensive 20mm f/2.8 plus 50 and 85mm
f/1.8 lenses; and there are 30mm, 50mm and 85mm f/1.4 lenses
which are not so inexpensive.
If your budget allows, the f/1.4 lenses are definitely better,
but if the budget is tight it might be necessary to select just
one of the f/1.8 lenses. (Note that for Nikon, the 50mm f/1.8 is
very good and very inexpensive.)
For a general purpose lense, Nikon has an 18-70mm zoom lense
that is wonderful, but far too slow for "low light conditions".
I would consider any of the low end Nikon DSLRs, with the
18-70mm zoom as a kit lense; then look on eBay to find the fast
fixed focal length lense that suits your style.
David Dyer-Bennet
Troll.
ray
> ray <r...@zianet.com> wrote:
>>On Wed, 07 Mar 2007 04:03:00 -0800, ipy2006 wrote:
>>
>>> I have to shoot action photos in low light conditions. What is the
>>> best DSLR for this purpose?
>>> Thanks,
>>> Yip
>>
>>I should think the 'best' solution would be a film SLR with high speed
>>film. I don't think the practical ISO ranges available on DSLRs yet match
>>what is available with film.
>
> Digital is significantly better at higher ISOs.
I see. I don't suppose you'd have a reference to a definitive analysis?
Frank ess
Troll nourisher.
nospam
> >>I should think the 'best' solution would be a film SLR with high speed
> >>film. I don't think the practical ISO ranges available on DSLRs yet match
> >>what is available with film.
> >
> > Digital is significantly better at higher ISOs.
>
> I see. I don't suppose you'd have a reference to a definitive analysis?
<http://www.clarkvision.com/imagedetail/film.vs.digital.summary1.html>
basically, unless one is using fine grain film, pretty much any digital
slr is going to be better, especially at higher iso.
Floyd L. Davidson
>On Wed, 07 Mar 2007 09:13:36 -0900, Floyd L. Davidson wrote:
>
>> ray <r...@zianet.com> wrote:
>>>On Wed, 07 Mar 2007 04:03:00 -0800, ipy2006 wrote:
>>>
>>>> I have to shoot action photos in low light conditions. What is the
>>>> best DSLR for this purpose?
>>>> Thanks,
>>>> Yip
>>>
>>>I should think the 'best' solution would be a film SLR with high speed
>>>film. I don't think the practical ISO ranges available on DSLRs yet match
>>>what is available with film.
>>
>> Digital is significantly better at higher ISOs.
>
>I see. I don't suppose you'd have a reference to a definitive analysis?
http://www.clarkvision.com/imagedetail/film.vs.digital.summary1.html
http://www.sphoto.com/techinfo/dslrvsfilm.htm
http://photo.net/learn/optics/digitaloptics/
http://www.luminous-landscape.com/reviews/cameras/d60/d60.shtml
The controversy seems to be whether that has only been recently
true, or whether in fact the Nikon D1 (1999) out performed film
at high ISOs.
David Dyer-Bennet
> ray <r...@zianet.com> wrote:
>> On Wed, 07 Mar 2007 09:13:36 -0900, Floyd L. Davidson wrote:
>>
>>> ray <r...@zianet.com> wrote:
>>>> On Wed, 07 Mar 2007 04:03:00 -0800, ipy2006 wrote:
>>>>
>>>>> I have to shoot action photos in low light conditions. What is the
>>>>> best DSLR for this purpose?
>>>>> Thanks,
>>>>> Yip
>>>> I should think the 'best' solution would be a film SLR with high speed
>>>> film. I don't think the practical ISO ranges available on DSLRs yet match
>>>> what is available with film.
>>> Digital is significantly better at higher ISOs.
>> I see. I don't suppose you'd have a reference to a definitive analysis?
>
> http://www.clarkvision.com/imagedetail/film.vs.digital.summary1.html
> http://www.sphoto.com/techinfo/dslrvsfilm.htm
> http://photo.net/learn/optics/digitaloptics/
> http://www.luminous-landscape.com/reviews/cameras/d60/d60.shtml
>
> The controversy seems to be whether that has only been recently
> true, or whether in fact the Nikon D1 (1999) out performed film
> at high ISOs.
Yeah, and I wouldn't know about that.
My Epson 850Z did *not* outperform film at ASA 400. My Fuji S2 *did*
outperform film (in subjective terms; I'm not working from a quantified
measure of picture quality that's valid across both film and digital!)
at ISO 1600 to ISO 400 at least.
John Sheehy
@h3g2000cwc.googlegroups.com:
> I read some review that Canon Eos Digital Rebel xTi DSLR is good low
> lighting. Nikon D80 was good but the article said more as a available-
> light camera.
I agree that the XTi is "good" in low light; it's better than older Canons
like the 10D and 300D, and better than most current CCD DSLRs from other
manufacturers, but it is still a good notch below the 30D. The read noise
of the 30D is 0.6 stops lower in ADUs (RAW levels), and the XTi is 0.5 stop
less sensitive (RAW signal for a fixed illumination and exposure). The XTi
and 30D both meter for approximately 120% of the stated ISO, but the XTi
winds up with an extra 0.5 stops of headroom. So. all told, the practical
noise floor is 1.1 stops higher with the XTi, for the same real (not
metered) exposure.
The XTi seems to be a better imager at ISOs 100 and 200, though, with more
pixels and less read noise.
--
<>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
John P Sheehy <J...@no.komm>
><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><
acl
> "nospam" <nos...@nospam.invalid> schreef in berichtnews:070320070812162004%nos...@nospam.invalid...
>
> > In article <pan.2007.03.07.15.53.05.559...@zianet.com>, ray
> > <r...@zianet.com> wrote:
>
> >> I should think the 'best' solution would be a film SLR with high speed
> >> film. I don't think the practical ISO ranges available on DSLRs yet match
> >> what is available with film.
>
> > digital is *much* better than film at high iso.
>
> That is *very much* dependand by brand.
>
Well, can you name a film that is better than the Nikon D200 at, say,
ISO 1600? (noise is not its strongest point).
Or do you mean something like "sensor/pixel size" by brand?
Dr. Joel M. Hoffman
>> best DSLR for this purpose?
>
>need. If not, you might need to spend about $1000 or even several
You don't need to spend $1,000 for a lens that does better in low
light than the kit lens. A good 50mm prime will do very well in low
light. And the Canon 30D does amazingly well at ISO1600.
On the other hand, if you're taking pictures in low light of things
that aren't moving, and if you can't use a tripod, then the slower IS
lenses (17-85, e.g.) may be better than the 50mm prime.
For that matter, if you you really have VERY little light, then
nothing will help.
But basically, the Canons do a bit better under low light than the
Nikons, and you want as fast a lens as you can afford.
-Joel
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ASAAR
> I think he will need a wider lens for groups of people in a kitchen
> unless it's a huge kitchen. I initially only saw the $1000 budget but
> with $1500 he could get a Nikon D50, Sigma 30mm f/1.4 and 18-70mm
> lenses. I don't know the Canon options as well.
It depends on the kitchen. Mine might need an ultra-wide. :)
For many, 18mm is probably wide enough. A turkey in a pan isn't
going to be as quick as a toddler in the living room or a frisky
pet, and if the rest of the shot is sharp, the slight blur of a
stirring spoon might even be desirable. If the kitchen is small and
dim, then the Sigma 30mm f/1.4 might be a good addition, but I'd
hold off on it for at least long enough to find out if the 18-70mm
lens's aperture is too small. A bigger problem in cramped quarters
will be dealing with harsh and very uneven lighting if a flash has
to be used, but dealing with that can come later, as I don't think
that the solutions would be effected very much by the choices of
DSLR body and lenses, as long as there's enough left in the budget.
MarkË›
In my browser, this particular troll is only an echo... :)
--
Images (Plus Snaps & Grabs) by Mark² at:
www.pbase.com/markuson
ray
I certainly was not referring to cheapie film off the wall at Walgreen's.
I plan to delve into some of the references above, but I'd still be
surprised if a DSLR will out perform high quality, high speed film at low
light levels.
ray
> ray <r...@zianet.com> wrote:
>>On Wed, 07 Mar 2007 09:13:36 -0900, Floyd L. Davidson wrote:
>>
>>> ray <r...@zianet.com> wrote:
>>>>On Wed, 07 Mar 2007 04:03:00 -0800, ipy2006 wrote:
>>>>
>>>>> I have to shoot action photos in low light conditions. What is the
>>>>> best DSLR for this purpose?
>>>>> Thanks,
>>>>> Yip
>>>>
>>>>I should think the 'best' solution would be a film SLR with high speed
>>>>film. I don't think the practical ISO ranges available on DSLRs yet match
>>>>what is available with film.
>>>
>>> Digital is significantly better at higher ISOs.
>>
>>I see. I don't suppose you'd have a reference to a definitive analysis?
>
> http://www.clarkvision.com/imagedetail/film.vs.digital.summary1.html
> http://www.sphoto.com/techinfo/dslrvsfilm.htm
> http://photo.net/learn/optics/digitaloptics/
> http://www.luminous-landscape.com/reviews/cameras/d60/d60.shtml
>
> The controversy seems to be whether that has only been recently
> true, or whether in fact the Nikon D1 (1999) out performed film
> at high ISOs.
Interesting references. Only problem is that they seem to be addressing
what might be achieved under optimal conditions rather than addressing
high ISO - low light action shots. I'm still not convinced.
David Dyer-Bennet
Several of us who've played with high-speed film for multiple decades,
and digital for somewhat less, have told you that in our experience
digital is *much* better than film at high ISO. This is also a truism
repeated in nearly any introductory discussion of digital photography
aimed at people used to film (the fact that you can use ISO at least a
stop faster than you're used to for the same quality results).
Skepticism is healthy in a broad sort of way, but I'd suggest that this
sort of widespread consensus contrary to your beliefs should be at least
pushing you to doubt yourself, and to be actively seeking to run your
own comparison tests.
If you in fact care, of course; you may have strong opinions but not
actually *use* high ISO so you don't really care. In which case it
might be better to just drop the discussion.
Scott W
shots with available light that I could never get before. The scans I
have seen of even ISO 400 film have looked pretty bad, I don't want to
even think about how bad ISO 1600 color print film would be.
And the DSLRs just keep getting better, our 20D does very well at 1600
and is very usable at 3200, but I have seen test shots from the 1D
mark 3 at 6400 that just blow me away.
Scott
Paul Rubin
> And the DSLRs just keep getting better, our 20D does very well at 1600
> and is very usable at 3200, but I have seen test shots from the 1D
> mark 3 at 6400 that just blow me away.
I don't see how the 1Dmk3 does better given the various observations
that the 20D's low light performance is limited basically by photon noise.
ray
That's another point that the OP failed to mention: is the ultimate
objective to have an image in the computer to manipulate or just to have
some good prints? That, IMHO, would make a difference.
Scott W
The 1D III has a larger sensor then the 20D, and they have impoved the
fill factor
on the 1D III, less dead space between pixels.
Scott
ray
Since I don't have $1500 to blow on a digital SLR, I don't plan on doing
my own comparison tests any time soon. I will be experimenting a little
with my Kodak P850 to see what it's limitations are. I also have my trusty
old Minolta SRT202 which I still put a roll through every once in a while
- particularly doing wildlife shots at Yellowstone. I've not much doubt
that under ideal conditions digital produces shots that are quite fine
enough. The OP did not state (as I recall) whether the ultimate product
would be files for editing on the computer or prints - I suspect that
could easily swing the pendulum one way or the other. BTW - I've produced
shots from a 1mp Kodak DC210+ printed to 8x10 that look pretty damned good
- but that was, again, under the best of circumstances.
>
> If you in fact care, of course; you may have strong opinions but not
> actually *use* high ISO so you don't really care. In which case it
> might be better to just drop the discussion.
I don't often use high ISO - I hope, as I said, to do some shooting in
that area as time permits.
Scott W
> That's another point that the OP failed to mention: is the ultimate
> objective to have an image in the computer to manipulate or just to have
> some good prints? That, IMHO, would make a difference.
My own experience has been that I can get far better prints by
scanning my own negatives and printing from the image files rather
then just sending the film to a lab.
Scott
UC
Moron.
David Dyer-Bennet
"Good enough" (or fine enough) is an extremely important milestone in
the development of a technology, definitely.
I've got at least 5 8x10 prints from a 2 megapixel Epson 850Z camera
framed and on the walls in the house here; that's less than 150 pixels
per linear inch, and they "shouldn't" look that good. My examples are
also "best case" situations, and I couldn't count on 2mp for 8x10 reliably.
I don't expect you to buy the equipment you think won't work too well
just to run tests, not; that wouldn't be reasonable.
I will tell you, as a matter of personal experience, confirmed by LOTS
of paper and online writers, that DSLRs perform *much* better than the
P&S cameras. Sensor size is a key factor in image quality.
There are a LOT of high-ISO pictures in my online snapshot album from my
old Fuji S2 and my current Nikon D200, with the full EXIF data so you
can tell what ISO they're shot at (and what camera, there are a couple
other digital cameras contributing too). I'd be willing to send you the
camera original of a modest number of them (your choice) for careful
comparison and analysis, and use in a web page or article if you want to
take the trouble to write up your results carefully. (The S2 was
2003-spring 2006, when I got the D200; the root of the snapshot album
site is at <http://dd-b.net/dd-b/SnapshotAlbum/data/>.).
This one from a wake for a good friend, last October, was only ISO 800,
but I gotta say that for me, TRI-X at 400 doesn't look this good.
Or if you prefer color,
<http://dd-b.net/cgi-bin/picpage.pl/dd-b/SnapshotAlbum/data/2006/10270-jmf-memorial?pic=ddb%2020061027%20010-180;IPTC=no;EXIF=yes>.
Paul Rubin
> > I don't see how the 1Dmk3 does better given the various observations
> > that the 20D's low light performance is limited basically by photon noise.
> The 1D III has a larger sensor then the 20D, and they have impoved the
> fill factor on the 1D III, less dead space between pixels.
Oh, both good points, though I thought the 1D3 uses a CMOS sensor
which used to mean that there was some penalty because of digitization
circuitry using up some of the active area that was somehow kept
available for light collection with CCD sensors.
nospam
<r...@zianet.com> wrote:
> Since I don't have $1500 to blow on a digital SLR, I don't plan on doing
> my own comparison tests any time soon.
digital slrs start around $500ish.
ray
Right. With a fast short lens and a good 400mm lens.
ray
I would certainly concur with that.
>
> I don't expect you to buy the equipment you think won't work too well
> just to run tests, not; that wouldn't be reasonable.
>
> I will tell you, as a matter of personal experience, confirmed by LOTS
> of paper and online writers, that DSLRs perform *much* better than the
> P&S cameras. Sensor size is a key factor in image quality.
I've come to the same conclusion. My current requirements evolve much more
around portability and long lenses than getting the ultimate performance.
When I'm hiking (or snowshoeing) for several miles, I want to keep things
pared down as much as possible. When that phase of my requirements change
significantly, I will be looking with more emphasis on sensor size than
number of pixels.
>
> There are a LOT of high-ISO pictures in my online snapshot album from my
> old Fuji S2 and my current Nikon D200, with the full EXIF data so you
> can tell what ISO they're shot at (and what camera, there are a couple
> other digital cameras contributing too). I'd be willing to send you the
> camera original of a modest number of them (your choice) for careful
> comparison and analysis, and use in a web page or article if you want to
> take the trouble to write up your results carefully. (The S2 was
> 2003-spring 2006, when I got the D200; the root of the snapshot album
> site is at <http://dd-b.net/dd-b/SnapshotAlbum/data/>.).
>
> This one from a wake for a good friend, last October, was only ISO 800,
> but I gotta say that for me, TRI-X at 400 doesn't look this good.
>
> <http://dd-b.net/cgi-bin/picpage.pl/dd-b/SnapshotAlbum/data/2006/10270-jmf-memorial?pic=ddb%2020061027%20010-170>
>
> Or if you prefer color,
> <http://dd-b.net/cgi-bin/picpage.pl/dd-b/SnapshotAlbum/data/2006/10270-jmf-memorial?pic=ddb%2020061027%20010-180;IPTC=no;EXIF=yes>.
Thanks for the references - I'll have a look at your shots.
Scott W
> Since I don't have $1500 to blow on a digital SLR, I don't plan on doing
> my own comparison tests any time soon. I will be experimenting a little
> with my Kodak P850 to see what it's limitations are.
come
close to the ISO performance that a DSLR will have, its sensor is just
too
small for that. It would be a mistake to judge what a DLSR is capable
of based on a point and shoot digital. The point and shoot cameras
that I have are pretty much limited to ISO 100 or less.
To see just how much better a DSLR is first look at how the P850 does
at ISO 400
<http://www.dpreview.com/reviews/kodakp850/page11.asp>
Now look at how the a number of DLSRs do at ISO 800 and 1600
<http://www.dpreview.com/reviews/canoneos400d/page27.asp>
>I also have my trusty
> old Minolta SRT202 which I still put a roll through every once in a while
> - particularly doing wildlife shots at Yellowstone. I've not much doubt
> that under ideal conditions digital produces shots that are quite fine
> enough.
The reality is that a DSLR is far better at getting the good shots
when conditions are not idea, it is far better in low light and it is
far better when white balance might be tricky.
>The OP did not state (as I recall) whether the ultimate product
> would be files for editing on the computer or prints - I suspect that
> could easily swing the pendulum one way or the other.
Does not matter if you are going for prints or files a DSLR will do
way better in low
light.
> BTW - I've produced
> shots from a 1mp Kodak DC210+ printed to 8x10 that look pretty damned good
> - but that was, again, under the best of circumstances.
I have never gotten a 8 x 10 print from a 1 MP camera that I really
liked, they always looked really soft to me.
> I don't often use high ISO - I hope, as I said, to do some shooting in
> that area as time permits.- Hide quoted text -
If you use either film or your point and shoot you will likely get
frustrated pretty fast,
unless you do B/W and really like grain, some people do.
Scott
John Sheehy
news:Xns98ECB22A8...@130.81.64.196:
> So. all told, the practical noise floor
> is 1.1 stops higher with the XTi, for the same real (not metered)
> exposure.
I made a distinction there, but in this specific case, both meter about the
same, anyway.
> The XTi seems to be a better imager at ISOs 100 and 200, though, with
> more pixels and less read noise.
This is in the sense that the XTi has a lower noise floor than any Canon
DSLRs except the 1-series at ISOs 100 and 200, relative to maximum signal.
If you let the camera meter the scene without an extra 1/2 stop of EC,
there will be more noise in the shadows in the XTi. Fortunately, the -2
contrast setting in the XTi recognizes this extra headroom, and rolls it
well into the JPEGs, so a white or green highlight clips in the review and
histogram just barely below where the RAW data does, so you can use the
histogram to feel out white and green RAW highlights.
Floyd L. Davidson
You do have to actually *read* them, not just scan them. The do
each address it specifically, though some in less detail than
others. The point in the number of cites was merely to
demonstrate there is a consensus. For specifics you can't do
better than the discussion by Roger N. Clarke.
Regardless, you've made it quite clear that you are not
interested in definitive analysis of the question; and won't
accept anything that disturbs your current bias.
I don't have the time to waste with detailed discussion of the
above reference under those circumstances.
John Sheehy
news:7x1wjzr...@ruckus.brouhaha.com:
> I don't see how the 1Dmk3 does better given the various observations
> that the 20D's low light performance is limited basically by photon
> noise.
It is a widely held belief that current cameras are limited mainly by
photon noise, and Roger Clark's work is often quoted and referenced to
support it, but I, for one, don't believe it. I believe that photon noise
is a relatively pleasant-looking noise, and it is ruined by patterned read
noises (both blackframe offset, and scalar illumination noises), which have
much more visual power than the randomly-distibuted poisson shot noise.
Take any Canon RAW file underexposed by several stops, and push it, What
do you see? Bands of color running horizontally, sometimes vertically.
This is not shot noise that is ruining the shadows. Look how high read
noise is in electrons, at the lowest ISOs - it is incredibly high, and
trashes the excellent shadows captured in the sensor wells. Shot noise is
the least of our digital imaging problems, IMO, especially with large
sensors.
That said, Canon does claim less wasted space on the sensor (higher fill
factor) over the mkII, and greater quantum efficiency, so, ISO 50 may be
able to have full DR, unlike the mkII, *and* more photons may be collected
for the same real-world absolute exposure.
David J. Littleboy
"John Sheehy" <J...@no.komm> wrote:
>
> Take any Canon RAW file underexposed by several stops, and push it, What
> do you see? Bands of color running horizontally, sometimes vertically.
> This is not shot noise that is ruining the shadows. Look how high read
> noise is in electrons, at the lowest ISOs - it is incredibly high, and
> trashes the excellent shadows captured in the sensor wells.
In the 5D and 1Dmk2, the ISO 100 read noise looks to me to be dominated by
quantization errors; the bit depth of the A/D converter is two bits shy of
what's needed, maybe three. The dynamic range at ISO 100 to 400 is simply
consistent with a 12-bit A/D converter. It's only at ISO 800 and above that
other noise sources intrude.
That's why the D200 has the same ISO 100 dynamic range as the 5D.
> Shot noise is
> the least of our digital imaging problems, IMO, especially with large
> sensors.
I'm not seeing pattern noise in pused images. Here's a 5D ISO 3200 file
pushed 3 stops. Straight from Lightroom with noise reduction (and
sharpening) turned off.
http://www.pbase.com/davidjl/image/75374090/original
This is seriously amazing stuff. At ISO 6400, the 5D is producing images
competitive with the dreck 35mm users get with Tri-X in Rodinal (ISO 400).
Here's what you get with noise reduction and a touch of sharpening.
http://www.pbase.com/davidjl/image/75359389/original
> That said, Canon does claim less wasted space on the sensor (higher fill
> factor) over the mkII, and greater quantum efficiency, so, ISO 50 may be
> able to have full DR, unlike the mkII, *and* more photons may be collected
> for the same real-world absolute exposure.
ISO 50 will remain problematic, since the well depth is inadequate.
David J. Littleboy
Tokyo, Japan
Paul Rubin
> I'm not seeing pattern noise in pused images. Here's a 5D ISO 3200 file
> pushed 3 stops. Straight from Lightroom with noise reduction (and
> sharpening) turned off.
>
> http://www.pbase.com/davidjl/image/75374090/original
You mean this is at 25,600? Pretty cool. I've seen TMZ pushed to
that speed and maybe the grain isn't worse, but the TMZ has no
tonality to speak of with that much pushing.
David J. Littleboy
>> pushed 3 stops. Straight from Lightroom with noise reduction (and
>> sharpening) turned off.
>>
>> http://www.pbase.com/davidjl/image/75374090/original
>
> You mean this is at 25,600?
Exactly!
> Pretty cool. I've seen TMZ pushed to
> that speed and maybe the grain isn't worse, but the TMZ has no
> tonality to speak of with that much pushing.
I wonder if you are comparing apples to apples: that's a 100% crop from at
12.7MP original. Even with that much noise, that's a lot of pixels. I'd
think pushed film viewed at that resolution would be a major disaster.
ray
> On Mar 8, 7:45 am, ray <r...@zianet.com> wrote:
>> Since I don't have $1500 to blow on a digital SLR, I don't plan on doing
>> my own comparison tests any time soon. I will be experimenting a little
>> with my Kodak P850 to see what it's limitations are.
> The Kodak may be able to produce a good looking image but it will not
> come
> close to the ISO performance that a DSLR will have, its sensor is just
> too
> small for that. It would be a mistake to judge what a DLSR is capable
> of based on a point and shoot digital. The point and shoot cameras
> that I have are pretty much limited to ISO 100 or less.
Those are obvious points. Manual says the P850 will do iso 800 at 1.2 mp -
400 otherwise. Certainly I would not judge what a dslr costing several
times more by it. It's what I have, and happens to fit my current
requirements better than a larger camera. I've just not had time to do
much experimenting yet.
>
> To see just how much better a DSLR is first look at how the P850 does
> at ISO 400
> <http://www.dpreview.com/reviews/kodakp850/page11.asp>
> Now look at how the a number of DLSRs do at ISO 800 and 1600
> <http://www.dpreview.com/reviews/canoneos400d/page27.asp>
>
>
One thing I note is that they advise shooting raw with the P850 at 400 - I
routinely shoot raw on the P850 - something you can't do with many P&S
cameras.
>>I also have my trusty
>> old Minolta SRT202 which I still put a roll through every once in a while
>> - particularly doing wildlife shots at Yellowstone. I've not much doubt
>> that under ideal conditions digital produces shots that are quite fine
>> enough.
> The reality is that a DSLR is far better at getting the good shots
> when conditions are not idea, it is far better in low light and it is
> far better when white balance might be tricky.
That's what everyone seems to be saying.
>
>>The OP did not state (as I recall) whether the ultimate product
>> would be files for editing on the computer or prints - I suspect that
>> could easily swing the pendulum one way or the other.
> Does not matter if you are going for prints or files a DSLR will do
> way better in low
> light.
>
>> BTW - I've produced
>> shots from a 1mp Kodak DC210+ printed to 8x10 that look pretty damned good
>> - but that was, again, under the best of circumstances.
>
> I have never gotten a 8 x 10 print from a 1 MP camera that I really
> liked, they always looked really soft to me.
>
>
>> I don't often use high ISO - I hope, as I said, to do some shooting in
>> that area as time permits.- Hide quoted text -
>
> If you use either film or your point and shoot you will likely get
> frustrated pretty fast,
> unless you do B/W and really like grain, some people do.
What I do is a lot of hiking and snowshoeing. I don't relish packing ten
pounds of dslr and lenses along. For right now, the P850 seems to fill the
bill. I don't do much B/W, I don't care for a lot of grain, I fairly
frequently shoot wildlife at some distance, so will use a big zoom. Doubt
I will get much frustrated - I believe I know what to expect - I've been
using digital for a number of years - Kodak DC210+; Minolta S414; now the
P850. I'll be sure and let you know if my frustration level gets out of
control.
>
> Scott
John Sheehy
news:esq8u8$9tm$1...@nnrp.gol.com:
> In the 5D and 1Dmk2, the ISO 100 read noise looks to me to be
> dominated by quantization errors;
The standard deviation of an ISO 100 blackframe is about 1.26 ADU on a
mkII, and 1.97 on a 5D (it's 0.9 ADU on the Pentax K10D). These are all
quite a bit more than what is possible with quantization, and the ranges
near black are where quantization is potentially most harmful.
With the 14-bit 1DmkIII, the blackframe read noise at ISO 100 is 4.88
ADU; not an improvement over the 1.26 of the 12-bit successor, and a hint
that the mkII's 1.26 has nothing much to do with posterization (and how
do you posterize black, anyway?).
> the bit depth of the A/D converter
> is two bits shy of what's needed, maybe three.
It's definitely shy of what is usable within the sensor wells. We really
can't tell at what point in the signal chain the high read noise (in
electrons) comes from, but it is really there, so even if sensor wells
are only limited by shot noise (and dark current noise, when applicable),
the *camera* is still subjected to high read noise. The blackframe read
noise at ISO 100 is generally in the 20 to 30 electron range. That means
that two neighboring pixels could be as much as 100 electrons off, as far
as their recorded and real differences are concerned.
> The dynamic range at
> ISO 100 to 400 is simply consistent with a 12-bit A/D converter.
There really aren't that many samples of unique camera arrangements where
you can observe one effect in isolation. We are victims of all kinds of
coincidences in our observations.
Anyway, regardless whether its the ADC, or the first amplifiers, the
camera, somewhere, is picking up tremendous read noise, as measured in
relative signal electrons, at the lowest ISOs electrons. You don't need
more than 12 bits to get more DR out of these cameras; you need less read
noise. You want just enough read noise to dither away any posterization.
There is *far* more than what is needed for that in current cameras.
> It's
> only at ISO 800 and above that other noise sources intrude.
>
> That's why the D200 has the same ISO 100 dynamic range as the 5D.
Does it? Most of the tests I've seen are about the RAW conversions,
which tend to equalize things a bit; not RAW comparisons. The D200 may
have less shot noise, but I think it also has more read noise, IIRC, and
stronger banding noise (horizontal, not vertical as in those high-
contrast edge problems), hidden by even stronger 2D random read noise.
Nikon also clips their RAW data at the blackpoint; not a very good idea
if you're really interested in clean deep shadows.
>> Shot noise is
>> the least of our digital imaging problems, IMO, especially with large
>> sensors.
>
> I'm not seeing pattern noise in pused images. Here's a 5D ISO 3200
> file pushed 3 stops. Straight from Lightroom with noise reduction (and
> sharpening) turned off.
>
> http://www.pbase.com/davidjl/image/75374090/original
There's a strong horizontal banding component there. Load it into
photoshop, and open the motion blur tool. Set it to 0 degrees, and 50
pixels. Then, change it to 90 degrees. See the difference? The
horizontal blur creates much stronger horizontal streaks than the
vertical does vertical, because there is horizontal streaking in the
image, the pattern of which is masked by the more random 2D noise, but
the strength of which is not.
acl
> which tend to equalize things a bit; not RAW comparisons. The D200 may
> have less shot noise, but I think it also has more read noise, IIRC, and
> stronger banding noise (horizontal, not vertical as in those high-
> contrast edge problems), hidden by even stronger 2D random read noise.
Where did you see this horizontal banding? I've never seen anything
like that in my raw files, only vertical bands, eg here:
http://www.pbase.com/al599/image/74719850
I once took a black frame, dumped the data using dcraw, and then
looked at the fourier transform of parts of the frame, and saw a
smoothed spike indicating patterns periodic in the horizontal
direction (ie vertical banding). But that was what I was looking for
so maybe I missed something. Or maybe it is dcraw. I don't know. So,
how did you see horizontal banding?
John Sheehy
news:1173408339.9...@v33g2000cwv.googlegroups.com:
> Where did you see this horizontal banding?
It was not readily visible in the D200, for the reason I mentioned. The
ratio of 2D noise to 1D noise determines how well you can see the 1D noise.
I extracted the 1D components from the image, from an unilluminated area,
and the intensity was actually greater than with my Canon 20D, which has a
reputation for banding at high ISOs. I subsequently did the same for
several cameras by various manufacturers, and found that they all had
banding, and all had stronger banding than the 20D, but their 2D random
noise was so much more so that the banding was masked.
By banding, I mean offsets in the RAW data on a line-by-line basis, visible
or not. Even when banding is not visible as "banding", it's removal still
makes the remaining noise look much more natural (except, of course, for
the inherent pixel grid of both the signal and noise), despite the fact
that the standard deviation may drop by less than 1%. Any patterned or 1D
noise, is much more destructive per unit of standard deviation, than 2D
random noise. Even binning and downsampling fail to reduce 1D noise at the
rate it reduces 2D noise; same for viewing full-res images from a distance,
or printed small; the lines do not fade away, whether they are perceived as
lines or not.
I've taken blackframes from my Canons and binned them down to ridiculous
levels, and all that remains is horizontal and vertical lines with no 2D
random noise left; the bands are resilient.
Roger N. Clark (change username to rnclark)
> "Paul Rubin" <http://phr...@NOSPAM.invalid> wrote:
>
>>"David J. Littleboy" <dav...@gol.com> writes:
>>
>>>I'm not seeing pattern noise in pushed images. Here's a 5D ISO 3200 file
>>>pushed 3 stops. Straight from Lightroom with noise reduction (and
>>>sharpening) turned off.
>>>
>>>http://www.pbase.com/davidjl/image/75374090/original
>>
>>You mean this is at 25,600?
>
>
> Exactly!
David,
Pretty cool demonstration.
Here is pushing some other limits with a Canon 1D Mark II:
Night and Low Light Photography with Digital Cameras
http://www.clarkvision.com/photoinfo/night.and.low.light.photography
Figures 3a, 3b are 623 second exposures at ISO 1600.
Figure 4, set 2 equivalent to ISO 66,450!
Figure 4, set 3 is an average of 6 frames at ISO 374,000!
Figure 5, set 5 is a single frame at ISO 3,883,000 !!!
Figure 8: night scene at equivalent ISO 16,000.
Figure 9: night scene at equivalent ISO 64,000 (no dark subtraction).
Figure 12: night scene at equivalent ISO320,000 (with dark subtraction).
Figure 13: night scene: 64 frames averaged at ISO 320,000.
Try that with film: you would get nothing.
For Ray:
Electronic sensors have quantum efficiencies in the
30% range, and film a percent or so, so right there, one
sees that electronic sensors are much more sensitive.
Next combine the fact that there is a threshold with film
requiring a fair number of photons before a grain will
record the light, then add the fact of reciprocity failure
and there are significant technical reasons why film does not do
well in low light situations.
Add the above facts and it is no wonder why amateur astronomers
had pretty much abandoned film for digital cameras.
Amateur astronomers are getting much better astrophotos
with DSLRs than they every did with film, even when using
DSLRs on smaller telescopes in light polluted skies!
The results are truly astounding. For example:
a 27-minute exposure from light polluted Denver of the Pleiades:
http://www.clarkvision.com/galleries/gallery.astrophoto-1/web/m45-700MM-8534-8561_C16B-add27-v3-800.html
is better than I ever did with the best long exposure professional
astronomical film (103aF) from dark skies and longer exposures
with faster lenses.
Action: DSLRs produce better images at high ISO than any film
I ever used. E.g., here is a lion eating a zebra before
sunrise on the Serengeti a few weeks ago (1/250 sec at ISO 800):
http://www.clarkvision.com/galleries/gallery.africa/web/lion.c01.23.2007.JZ3F0240b-700.html
I couldn't have gotten much of an image with film pushed
to ISO 800. Other examples are on my web site.
Roger
Paul Rubin
> Here is pushing some other limits with a Canon 1D Mark II:
>
> Night and Low Light Photography with Digital Cameras
> http://www.clarkvision.com/photoinfo/night.and.low.light.photography
Wow, neat. The super-high-ISO examples have very visible horizontal
banding--what happens if you take that out with a notch filter?
Is there a feasible way to remove the Bayer filter from a DSLR sensor?
What about shorter exposures at super ISO's?
Roger N. Clark (change username to rnclark)
> Paul Rubin <http://phr...@NOSPAM.invalid> wrote in
> news:7x1wjzr...@ruckus.brouhaha.com:
>
>>I don't see how the 1Dmk3 does better given the various observations
>>that the 20D's low light performance is limited basically by photon
>>noise.
>
> It is a widely held belief that current cameras are limited mainly by
> photon noise, and Roger Clark's work is often quoted and referenced to
> support it, but I, for one, don't believe it. I believe that photon noise
> is a relatively pleasant-looking noise, and it is ruined by patterned read
> noises (both blackframe offset, and scalar illumination noises), which have
> much more visual power than the randomly-distibuted poisson shot noise.
Photon noise has a unique signature: it follows a square root dependence
on signal strength. You may not believe my results, but then how do you
explain all the other testing from the sensor manufacturers, university
testing, and other amateur astronomers testing that come to the
same conclusion and get the same results?
What noise source would you advocate that shows a square root dependence?
Why would the expected photon noise agree with derived quantum
efficiencies that agree with published QE levels?
Sure at the very low end, read noise, A/D quantization and pattern noise
is present, and that is also shown in the online test reports, but that
is usually below the level most people work at, and it is also
easily calibrated out for those who want to work at the lower levels
(e.g. astrophotographers. The implications of the 1D Mark III specs
imply significant improvements in this area too.
> That said, Canon does claim less wasted space on the sensor (higher fill
> factor) over the mkII, and greater quantum efficiency,
I didn't see any claim in increased quantum efficiency.
Efficiency due to fill factor and micro-lens improvements perhaps,
but not device quantum efficiency (although I would be happy
if I'm wrong here).
For those just joining, some relevant references on the subject:
http://www.clarkvision.com/imagedetail/index.html#sensor_analysis
Summary of data from many sources and also many references:
http://www.clarkvision.com/imagedetail/digital.sensor.performance.summary
Roger
ASAAR
<http://phr...@NOSPAM.invalid> wrote:
> Is there a feasible way to remove the Bayer filter from a DSLR sensor?
Would the Kodak DCS Pro 14n do? In a post from last July, a
Bystander giveth thusly:
> The 14 megapixel images it produces contain appreciably more
> information, as expressed in detail, colour, brightness range and so on
> than the old Kodachrome 25 slides in my library that I produced with the
> same lenses. They will reproduce excellently on A4 glossy magazine stock
> with as fine a screen lpi as you want.
but in concluding, all too quickly taketh away:
> My main anxiety about the Pro 14n, incidentally, is whether or not the
> batteries for it will still be available for the life of the camera. Use
> it in the right circumstances and the results are great -- but issues
> like slow startup, horrid noise levels in low light and surprising moire
> effects -- you wouldn't get that with Kodachrome -- easily justify the
> camera's discontinuance.
Paul Furman
> Paul Rubin wrote:
>
>>Is there a feasible way to remove the Bayer filter from a DSLR sensor?
As in B&W?
> Would the Kodak DCS Pro 14n do? In a post from last July, a
> Bystander giveth thusly:
Is this monocrome?
ASAAR
>> Would the Kodak DCS Pro 14n do? In a post from last July, a
>> Bystander giveth thusly:
>
> Is this monocrome?
Monochrome?? The Kodak DSLRs (IIRC) did away with the AA filters,
which allowed them to produce very sharp images, but which had
negative side effects, such as a tendency to produce more noticeable
moire, and some "stair step" artifacts by straight edges. There was
also a version of the Kodak that used a Canon body, the last one
being made by Sigma when Canon declined further participation. I
don't know if the Sigma version was or wasn't sold, just having read
about it in an article that was an extended "hands on" review of the
Nikon body version which had been used by the reviewer for several
months.
>>>The 14 megapixel images it produces contain appreciably
>>> more information, as expressed in detail, colour, . . .
Nope, not monochrome. :)
nospam
<cau...@22.com> wrote:
> There was
> also a version of the Kodak that used a Canon body, the last one
> being made by Sigma when Canon declined further participation. I
> don't know if the Sigma version was or wasn't sold, just having read
> about it in an article that was an extended "hands on" review of the
> Nikon body version which had been used by the reviewer for several
> months.
i saw someone using one about a year ago, so they've sold at least one.
acl
>
> > Where did you see this horizontal banding?
>
> It was not readily visible in the D200, for the reason I mentioned. The
> ratio of 2D noise to 1D noise determines how well you can see the 1D noise.
Well yes, but i can clearly see vertical bands and cannot see
horizontal bands at all (and not the high-contrast business, it's
patterned noise).
> I extracted the 1D components from the image, from an unilluminated area,
> and the intensity was actually greater than with my Canon 20D, which has a
> reputation for banding at high ISOs. I subsequently did the same for
> several cameras by various manufacturers, and found that they all had
> banding, and all had stronger banding than the 20D, but their 2D random
> noise was so much more so that the banding was masked.
Well ok I'll look again. I will be surprised if there's are horizontal
banding and I've misses it, but it could be there.
> By banding, I mean offsets in the RAW data on a line-by-line basis, visible
> or not. Even when banding is not visible as "banding", it's removal still
> makes the remaining noise look much more natural (except, of course, for
> the inherent pixel grid of both the signal and noise), despite the fact
> that the standard deviation may drop by less than 1%. Any patterned or 1D
> noise, is much more destructive per unit of standard deviation, than 2D
> random noise. Even binning and downsampling fail to reduce 1D noise at the
> rate it reduces 2D noise; same for viewing full-res images from a distance,
> or printed small; the lines do not fade away, whether they are perceived as
> lines or not.
Yes, I've noticed the same thing.
Roger N. Clark (change username to rnclark)
> "Roger N. Clark (change username to rnclark)" <user...@qwest.net> writes:
>> Here is pushing some other limits with a Canon 1D Mark II:
>>
>> Night and Low Light Photography with Digital Cameras
>> http://www.clarkvision.com/photoinfo/night.and.low.light.photography
>
> Wow, neat. The super-high-ISO examples have very visible horizontal
> banding--what happens if you take that out with a notch filter?
I have not tried that.
But all this talk about banding is a little
mis-informed in my opinion. John Sheehy seems to be saying that
because there is banding obvious at the low end is evidence for
non-photon noise sources. While true, one must look at the
level of the banding. For example, examine Figure 5 on the above web
page. Set 5 in Figure 5 shows banding at a similar level as the signal
in panels A and B (the left most two squares). But look at the table:
the photons per pixel is only 1.2 in panel A and 0.8 in panel B!
The read noise is 3.9 electrons, so the pattern noise is
about 1/4 the read noise. The problem is that our eyes plus
brain are very good at picking out patterns, whether that pattern
is below random noise, or embedded in other patterns.
It would be interesting to try some filtering on the images.
> Is there a feasible way to remove the Bayer filter from a DSLR sensor?
I do not know.
> What about shorter exposures at super ISO's?
Figure 12 on the above web page is a 1/20 second exposure at equivalent
ISO = 320,000. Do you want faster than that? It is simply a matter of photons
per pixel per exposure. I would not think faster exposures with
similar photons/pixel would appear any different. Longer at lower
light levels would not appear any different either until noise from
dark current starts to show. Dark current noise is the square root
of the dark current, and the 1D Mark II under the temperatures used
was around 0.03 electron/second. So a 10 second exposure would
about a 0.5 electron noise to the 3.9 electron read noise. Thermal
noise equals read noise after about 5 minutes.
Roger
acl
> >> Here is pushing some other limits with a Canon 1D Mark II:
>
> >> Night and Low Light Photography with Digital Cameras
> >> http://www.clarkvision.com/photoinfo/night.and.low.light.photography
>
> > Wow, neat. The super-high-ISO examples have very visible horizontal
> > banding--what happens if you take that out with a notch filter?
>
> I have not tried that.
>
> But all this talk about banding is a little
> mis-informed in my opinion. John Sheehy seems to be saying that
> because there is banding obvious at the low end is evidence for
> non-photon noise sources. While true, one must look at the
> level of the banding. For example, examine Figure 5 on the above web
> page. Set 5 in Figure 5 shows banding at a similar level as the signal
> in panels A and B (the left most two squares). But look at the table:
> the photons per pixel is only 1.2 in panel A and 0.8 in panel B!
> The read noise is 3.9 electrons, so the pattern noise is
> about 1/4 the read noise. The problem is that our eyes plus
> brain are very good at picking out patterns, whether that pattern
> is below random noise, or embedded in other patterns.
>
Actually I read his posts as saying, not that photon shot noise is
less important than you say in absolute terms, but that he finds
banding more disturbing. It seems to be a perceptual judgement; he
doesn't appear to be claiming anything quantitatively different from
what you say, just that it bothers him.
For what it's worth, I personally also find patterned noise much more
disturbing than random noise (I really don't mind random noise all
that much unless it gets to very high levels; of course it complicates
my postprocessing but that is another story). It also seems to be the
case that this patterned noise is more obvious to some people than to
others: I have prints from pushed high isos which I find have very
disturbing patterned noise (it jumps out at me immediately, and is
perceptually almost as strong as the image), while my wife and a
couple of friends don't notice it until I point it out, and then seem
to be unaware of it unless they consciously decide to "see" it. I
can't avoid seeing it at all. It seems to depend on the person; maybe
this is part of this confusion (or maybe not).
Roger N. Clark (change username to rnclark)
>
> Actually I read his posts as saying, not that photon shot noise is
> less important than you say in absolute terms, but that he finds
> banding more disturbing. It seems to be a perceptual judgement; he
> doesn't appear to be claiming anything quantitatively different from
> what you say, just that it bothers him.
>
> For what it's worth, I personally also find patterned noise much more
> disturbing than random noise (I really don't mind random noise all
> that much unless it gets to very high levels; of course it complicates
> my postprocessing but that is another story).
I too agree that pattern noise is more obvious that random noise.
Probably by at least a factor of ten. It is our eye+brain's
ability to pick out a pattern in the presence of a lot
of random noise that makes us able to detect many things
in everyday life. It probably developed as a necessary
thing for survival. But then it becomes a problem when we try
and make something artificial and we see the defects in it.
It gives the makers of camera gear quite a challenge.
Roger
John Sheehy
in news:45F160FC...@qwest.net:
> But all this talk about banding is a little
> mis-informed in my opinion. John Sheehy seems to be saying that
> because there is banding obvious at the low end is evidence for
> non-photon noise sources. While true, one must look at the
> level of the banding. For example, examine Figure 5 on the above web
> page. Set 5 in Figure 5 shows banding at a similar level as the
> signal in panels A and B (the left most two squares). But look at the
> table: the photons per pixel is only 1.2 in panel A and 0.8 in panel
> B! The read noise is 3.9 electrons, so the pattern noise is
> about 1/4 the read noise. The problem is that our eyes plus
> brain are very good at picking out patterns, whether that pattern
> is below random noise, or embedded in other patterns.
Yes, that is a problem, and that is exactly why you can't evaluate noise by
standard deviation alone. It doesn't even take human perception to focus
on the banding; binning and downsampling math focus on it too; an
blackframe from a 20D with 10x the total noise as the horizontal banding
component will show *only* banding noise, and no visible 2D noise at all,
if binned down far enough. I think that this fact speaks volumes as to how
useless standard deviations and S/N ratios based on them can be when
comparing different *characteristics* of noises.
> Thermal noise equals read noise after about 5 minutes.
Statistically, perhaps, but standard deviation does not tell the full
story. You can clearly compare the standard deviations of two noise
situations with the same characteristics, which only vary in terms of
amplitude, but noise comes in a variety of characteristics, and the
standard deviations are not necessarily related to the visual strength of
noise when the characteristics are different. Dark current noise is much
more visible than shot noise, with the same standard deviation, because
most of its energy goes into a minority of pixels.
John Sheehy
news:45F21915...@qwest.net:
> I too agree that pattern noise is more obvious that random noise.
> Probably by at least a factor of ten. It is our eye+brain's
> ability to pick out a pattern in the presence of a lot
> of random noise that makes us able to detect many things
> in everyday life. It probably developed as a necessary
> thing for survival. But then it becomes a problem when we try
> and make something artificial and we see the defects in it.
> It gives the makers of camera gear quite a challenge.
How does that co-exist with your conclusion that current cameras are
limited by shot noise?
Saying that current cameras are limited by shot noise means that all future
improvements lie purely in well depth, quantum efficiency, fill factor, and
sensor size (you'd probably add "large pixels", but I'd disagree). The
fact is, a 10:1 S:N on the 1DmkII at ISO 100 would be 1.5 stops further
below saturation, and 1:1 would be 4.3 stop further below it, if there were
no blackframe read noise
http://www.pbase.com/jps_photo/image/75392571
and that is only statistically, without consideration for the pattern noise
effects, which widen the visual gap even further.
Bart van der Wolf
"John Sheehy" <J...@no.komm> wrote in message
news:Xns98F06D6F9...@130.81.64.196...
> "Roger N. Clark (change username to rnclark)" <user...@qwest.net>
> wrote
> in news:45F160FC...@qwest.net:
>
>
>> picking out patterns, whether that pattern is below random
>> noise, or embedded in other patterns.
What's worse, we see non-existing patterns (e.g. a triangle in the
following link) because we want to:
<http://www.xs4all.nl/~bvdwolf/temp/Triangle-or-not.gif>.
> Yes, that is a problem, and that is exactly why you can't evaluate
> noise by standard deviation alone.
That depends what one wants to evaluate. Standard deviation (together
with mean) only tells something about pixel to pixel (or sensel to
sensel) performance. It doesn't allow to make valid judgements about
anything larger. Banding could be either calibrated out of the larger
structure, or an analysis of systematic noise should be done (and care
should be taken to not mistake Raw-converter effects for camera or
sensor array effects).
--
Bart
Bart van der Wolf
"John Sheehy" <J...@no.komm> wrote in message
> "Roger N. Clark (change username to rnclark)" <user...@qwest.net>
> wrote in
> news:45F21915...@qwest.net:
>
>> I too agree that pattern noise is more obvious that random noise.
>> Probably by at least a factor of ten. It is our eye+brain's
>> ability to pick out a pattern in the presence of a lot
>> of random noise that makes us able to detect many things
>> in everyday life. It probably developed as a necessary
>> thing for survival. But then it becomes a problem when we try
>> and make something artificial and we see the defects in it.
>> It gives the makers of camera gear quite a challenge.
>
> How does that co-exist with your conclusion that current cameras are
> limited by shot noise?
Shot noise is a physical limitation, not a man made one. The man made
limitations can be improved upon.
--
Bart
acl
> "John Sheehy" <J...@no.komm> wrote in message
>
> news:Xns98F06D6F9...@130.81.64.196...
>
> > wrote
> > innews:45F160FC...@qwest.net:
>
> >> The problem is that our eyes plus brain are very good at
> >> picking out patterns, whether that pattern is below random
> >> noise, or embedded in other patterns.
>
> What's worse, we see non-existing patterns (e.g. a triangle in the
> following link) because we want to:
> <http://www.xs4all.nl/~bvdwolf/temp/Triangle-or-not.gif>.
>
> > Yes, that is a problem, and that is exactly why you can't evaluate
> > noise by standard deviation alone.
>
> That depends what one wants to evaluate. Standard deviation (together
> with mean) only tells something about pixel to pixel (or sensel to
> sensel) performance. It doesn't allow to make valid judgements about
> anything larger.
As a matter of fact, they don't tell you anything (literally) about
pixel to pixel behaviour. If I tell you that a signal has mean zero
and given standard dev, what else can you tell me about it? Nothing.
It could be anything from an otherwise random time series to a sine
wave to a series of square waves to anything else. It's like knowing
the first two coefficients in an infinite power series (well that's
exactly what it is: the first two coefficients in an infinite power
series).
the reason people use the first two moments (mean and std) is that the
noises under consideration are often assumed to be gaussian, in which
case these 2 qtys completely characterise the noise. this is usually a
good approximation when the noise comes from many different sources.
Roger N. Clark (change username to rnclark)
I've said for at least a couple of years 14-bit or higher A/D are
needed too because current DSLRs are limited by 12-bit converters.
Some attacked me in this NG with the idea that "if more than 12-bits were
really needed, then why haven't camera manufacturers done it?"
We'll we now see they have, and I'm sure 14 or more-bits will become a
new standard in future DSLRs.
Regarding fixed pattern noise versus photon Poisson noise, your plot
and some simple illustrations show what is dominant. First clue,
look at the thousands of images on the net. How many show fixed
pattern noise? It is very rare. You tend to see fixed pattern noise
at the very lowest lows in an image. Second, if fixed pattern noise
is really a factor, guess what, you can calibrate most of it out with dark
frame subtraction. I think good examples of fixed pattern noise is
illustrated at:
http://www.clarkvision.com/photoinfo/night.and.low.light.photography
Figure 1, for example shows two merged low light images and fixed pattern
noise is not apparent, nor is it the dominant noise source in the image.
Figure 2 shows the black sky above the Sydney opera house in an ISO 100
20 second exposure. Fixed pattern noise is a little over 1 bit out of 12
in the raw data. It simply is not a factor. But where the scene has
signal, e.g. the lit roof, noise is proportional to the square root
of the signal strength, with photon noise up to 18 out of 4095
in the 12-bit raw file. So, over most of the range, photon noise
dominates. The low end, the bottom few values or bottom couple of bits,
is a combination of photon noise, read noise, and fixed pattern noise.
That gives about 10 bits out of 12 with photon noise as the dominant
noise source. Again, if you work at the low end, calibrate out
the majority of fixed pattern noise with dark frames.
Let's work an example.
Let's assume fixed pattern noise is more objectionable by
10 times random noise (this is a reasonable estimate
for me, and I find fixed pattern noise quite objectionable).
But then with processing, e.g. dark frame subtraction, it can
be reduced about 10x, then filtered and reduced more, all with
minimal impact on resolution. Random photon noise in an image
from can only be reduced by pixel averaging, thus reducing spatial
resolution.
Let's use your full well depth, rounding off to 53,000 electrons.
Fixed pattern noise in DSLRs like the 20D and 1D Mark II are between 1 and
2 bits in the A/D at low ISOs. At low signal levels, line-to-line
pattern noise is on the order of 7 electrons in the 1D Mark II, with
low frequency offset of a few tens of electrons (at ISO 100 fixed pattern
noise appears at about the 1-bit level, which is ~13 electrons. The low frequency
fixed pattern noise is entirely eliminated by a dark frame subtraction,
and line-to-line (what you call 1D) is reduced by about 10X with
dark frame subtraction.
So there are multiple conditions. Here is one example:
ISO 100, 1D Mark II, 53,000 electron full signal:
Signal Photon noise Read Noise Fixed-pattern What noise dominates
(elect- stops (electrons) +A/D noise noise Photon, read, or pattern
rons) (electrons) (electrons)
53,000 0 230 17 ~13 Photon
12,250 -4 110 17 ~13 Photon
3,312 -6 57 17 ~13 Photon
828 -8 29 17 ~13 Photon
207 -10 14 17 ~13 all 3 similar
51 -12 7 17 ~13 read + pattern
The above table demonstrate the the sensor has noise dominated by photon
statistics over most of its dynamic range. Each generation
of cameras that comes out pushed the floor where other noise sources in the
electronics show. It is likely we'll see the 1D Mark III push those limits
a stop or two lower. But photon noise remains and is the ultimate
limit.
Here is another test series that illustrates the above conclusions:
Digital Camera Raw Converter Shadow Detail and Image Editor Limitations:
Factors in Getting Shadow Detail in Images
http://www.clarkvision.com/imagedetail/raw.converter.shadow.detail
Figure 6 shows areas from +2 to -7.6 stops. But if you look at the different
raw conversions, you'll see widely different results and wildly different
fixed pattern noise. Then look at Figure 16: the camera jpeg looks pretty
clean with less pattern noise than some of the raw conversions.
So when you say you don't believe photon noise versus fixed pattern noise,
understand the effects of converters too.
Roger
Roger N. Clark (change username to rnclark)
And that is why people who evaluate sensors do more than simply
study the standard deviation of one image. To understand noise sources,
the standard procedure is to make a series of exposures and analyze
the results from the different test conditions. e.g.:
The Nikon D50 Digital Camera:
Sensor Noise, Dynamic Range, and Full Well Analysis
http://www.clarkvision.com/imagedetail/evaluation-nikon-d50
http://www.clarkvision.com/imagedetail/long-exposure-comparisons/index.html
and more at:
http://www.clarkvision.com/imagedetail/index.html#sensor_analysis
other:
http://www.astrosurf.org/buil/20d/20dvs10d.htm
Roger
acl
<usern...@qwest.net> wrote:
> And that is why people who evaluate sensors do more than simply
> study the standard deviation of one image. To understand noise sources,
Never claimed otherwise! By the way, why don't people study the full
power spectrum of the noise (ie of a blackframe)? That would give
quite a lot of information (it should allow distinguishing between the
white part of the noise and things like banding). And it should not be
too hard (eg with IRIS, split the channels and FT them). And if you do
that to an average of many frames, you'll be studying repeatable noise
only. Is there some particular reason this isn't done by anybody?
>
> The Nikon D50 Digital Camera:
> Sensor Noise, Dynamic Range, and Full Well Analysis
> http://www.clarkvision.com/imagedetail/evaluation-nikon-d50
>
That's quite interesting, why don't you include dark frames from more
cameras? I'd think that this would be quite useful for people
intending to do very low light work.
> http://www.clarkvision.com/imagedetail/long-exposure-comparisons/inde...
acl
> "John Sheehy" <J...@no.komm> wrote in message
>
> news:Xns98F06DCDB...@130.81.64.196...
>
> > wrote in
> >news:45F21915...@qwest.net:
>
> >> I too agree that pattern noise is more obvious that random noise.
> >> Probably by at least a factor of ten. It is our eye+brain's
> >> ability to pick out a pattern in the presence of a lot
> >> of random noise that makes us able to detect many things
> >> in everyday life. It probably developed as a necessary
> >> thing for survival. But then it becomes a problem when we try
> >> and make something artificial and we see the defects in it.
> >> It gives the makers of camera gear quite a challenge.
>
> > How does that co-exist with your conclusion that current cameras are
> > limited by shot noise?
>
> Shot noise is a physical limitation, not a man made one. The man made
> limitations can be improved upon.
>
The speed of light is also a physical limitation. Would you therefore
agree to the statement that the top speeds of current spaceships are
limited by the speed of light, and therefore we must work on finding
ways to circumvent that (rather than on finding some better propulsion
system than semi-controlled explosions) :)? (I'm not claiming that
banding really is the main limitation, by the way, I actually agree
with Roger and presumably you).
Roger N. Clark (change username to rnclark)
> On Mar 12, 2:53 pm, "Roger N. Clark (change username to rnclark)"
> <usern...@qwest.net> wrote:
>
>> And that is why people who evaluate sensors do more than simply
>> study the standard deviation of one image. To understand noise sources,
>
> Never claimed otherwise! By the way, why don't people study the full
> power spectrum of the noise (ie of a blackframe)? That would give
> quite a lot of information (it should allow distinguishing between the
> white part of the noise and things like banding). And it should not be
> too hard (eg with IRIS, split the channels and FT them). And if you do
> that to an average of many frames, you'll be studying repeatable noise
> only. Is there some particular reason this isn't done by anybody?
Time and effort--remember most are doing this for free out of
curisoty. I started doing this to try and get the best camera for
astrophotography. Then after seeing the trends, it became clear to
me that because the photon noise limit had been reached, one can
model and predict performance pretty closely. Now I find it
interesting about the claims coming out in some press releases
that seem to ignore physical reality ;-).
I and other astrophotographers tend to ignore fixed pattern noise
because we can calibrate most of it out of our images. If that is an
issue for other people, then I suggest they learn how to take
dark frames, average them, and subtract them from their images.
It is really pretty easy, but for best results, it needs to be
done on linear data. Another calibration that can improve images is
flat field calibration, which not only corrects for pixel to pixel
variations, but corrects for light fall-off from lenses.
But if someone wants to pay me to run more tests......
>> The Nikon D50 Digital Camera:
>> Sensor Noise, Dynamic Range, and Full Well Analysis
>> http://www.clarkvision.com/imagedetail/evaluation-nikon-d50
> That's quite interesting, why don't you include dark frames from more
> cameras? I'd think that this would be quite useful for people
> intending to do very low light work.
Again, time. I do have a fair amount of additional data for a number
of cameras but I have not had time to write it up.
Roger
>> http://www.clarkvision.com/imagedetail/long-exposure-comparisons
Doug McDonald
> acl wrote:
>> On Mar 12, 2:53 pm, "Roger N. Clark (change username to rnclark)"
>> <usern...@qwest.net> wrote:
>>
>>> And that is why people who evaluate sensors do more than simply
>>> study the standard deviation of one image. To understand noise sources,
>>
>> Never claimed otherwise! By the way, why don't people study the full
>> power spectrum of the noise (ie of a blackframe)? That would give
>> quite a lot of information (it should allow distinguishing between the
>> white part of the noise and things like banding). And it should not be
>> too hard (eg with IRIS, split the channels and FT them). And if you do
>> that to an average of many frames, you'll be studying repeatable noise
>> only. Is there some particular reason this isn't done by anybody?
>
> Time and effort--remember most are doing this for free out of
> curisoty. I started doing this to try and get the best camera for
> astrophotography. Then after seeing the trends, it became clear to
> me that because the photon noise limit had been reached, one can
> model and predict performance pretty closely.
I have the Canon 30D. I took a bunch of very underexposed shots
recently (no tripod at critical time) and found that background
subtraction didn't help much. The annoying noise is some sort
of horizontal banding or streaking (these are landscape shots).
Looks sort of like they scan the image TV-wise and this is 1/f noise
in the amplifiers.
Comments?
Doug McDonald
Roger N. Clark (change username to rnclark)
> I have the Canon 30D. I took a bunch of very underexposed shots
> recently (no tripod at critical time) and found that background
> subtraction didn't help much. The annoying noise is some sort
> of horizontal banding or streaking (these are landscape shots).
> Looks sort of like they scan the image TV-wise and this is 1/f noise
> in the amplifiers.
>
> Comments?
Doug,
Did you record the raw data, or just jpegs?
You need to record the dark frames under as close to the
same temperature as you can. With the lens cap on
(a dark or dimly lit room is fine too) set the
exposure time to the same as the exposures with the problem.
Record ten to twenty of the. If raw, convert them
with the same settings as your landscape image.
Average all the darks into one master dark, then
subtract the master dark from the landscape frames.
The closer the environmental conditions are to the
landscape images, the better the correction will be.
Roger
John Sheehy
news:et3rqs$m2h$1...@news.ks.uiuc.edu:
> I have the Canon 30D. I took a bunch of very underexposed shots
> recently (no tripod at critical time) and found that background
> subtraction didn't help much. The annoying noise is some sort
> of horizontal banding or streaking (these are landscape shots).
> Looks sort of like they scan the image TV-wise and this is 1/f noise
> in the amplifiers.
>
> Comments?
That's pretty typical of digital cameras in general; it is simply more
visible in cameras with a certain ratio of banding noise to total noise.
For the 30D it should be the same as the 20D (ignoring the 30D's fake,
extra ISOs):
http://www.pbase.com/jps_photo/image/65737967/original
The yellow line represents standard deviation of a blackframe, divided by
10 to fit in with the horizontal and vertical banding noises (they'd be
flat if the entire chart scaled for the the yellow line).
A few things become very clear here; the banding is generally only about
1/10 the strength of the total noise, and yet it is highly visible. With
more read noise, the banding would be less obvious (although it may still
contribute somewhat to visible noise, just without the obvious pattern).
The higher ISOs are all normalized for ISO 100; IOW the values for ISO
200 are divided by two, ISO 400 values are divided by 4, etc, so these
are proportional to electrons as units of noise. All noises decrease as
you get to the higher ISOs, and the total noise looks like it is leveling
off a bit from 800 to 1600, but still had room to improve a little at
3200, but 3200 is "fake" and is really ISO 1600 amplification, multiplied
by two, so it is exactly the same as ISO 1600. The horizontal banding is
still dropping dramatically from 800 to 1600, and seems to have the
capability of dropping even further if the amplification went to 3200 or
even 6400.
C J Campbell
> I have to shoot action photos in low light conditions. What is the
> best DSLR for this purpose?
> Thanks,
> Yip
For your budget, any of the cameras that handle well -- a D40 or Rebel
will work nicely, especially if you get a fast 50mm lens.
If you want to use flash, get a real flash unit.
--
Waddling Eagle
World Famous Flight Instructor
John Sheehy
in news:45F577C0...@qwest.net:
> I and other astrophotographers tend to ignore fixed pattern noise
> because we can calibrate most of it out of our images.
I'm not sure where "fixed pattern noise" came into play here; the issue
was read noise and one of it's components, 1-D noise. There is, for all
intents and purposes, zero fixed pattern noise in my 20D. Subtracting a
stack of black frames from a short exposure results in nothing but
slightly higher noise.
> If that is an
> issue for other people, then I suggest they learn how to take
> dark frames, average them, and subtract them from their images.
What about the read noise in short exposures?
> It is really pretty easy, but for best results, it needs to be
> done on linear data.
And in the case of Canons which have "negative noise" at the blackpoint,
it needs to be done without any clipping at the black level.
> Another calibration that can improve images is
> flat field calibration, which not only corrects for pixel to pixel
> variations, but corrects for light fall-off from lenses.
> But if someone wants to pay me to run more tests......
I don't feel like financing anything right now, but I might suggest that
when you have the time, you do a "gap" test of large vs small pixels.
Your 1DmkII vs S70 page seems to be about pixel size, but it is really
about sensor size. Do a test with a small-pixel camera, and the 1DmkII,
both using the same real focal length, the same Av value, the same Tv
value, the same ISO setting, of the same detailed subject from the same
distance. I guarantee that your big pixels will fall to the ground like
Goliath, when viewing the subject at any magnification, from both
downsampled to both upsampled, or printed large. This is the real test
of pixel size. What you seem to overlook in your analyses is the fact
that standard deviation is only *one* factor in the noise equation;
magnification is another, and the low noise of big pixels is visually
magnified when the pixels are magnified along with the subject.
I am quite certain that the only benefits of big pixels are:
1) quicker readout time and less storage requirements, and
2) slight benefit in photons collection rate per unit of sensor area due
to less wasted space on the sensor (not always realized, however; my
1.97u FZ50, for example, collects about the same number of photons per
unit of area as the 1DmkII, at RAW saturation for the same ISO).
Here is one of my tests; it needs to be redone, because I realized after
doing it that ISO 1600 on the FZ50 is crippled by a very bad amplifier,
that is worse than pushing 100 to 1600. Here is the original, however:
http://www.pbase.com/jps_photo/image/74020772
Don't forget that the 10D images would need to be sharpened more,
sharpening the noise as well.
acl
> that standard deviation is only *one* factor in the noise equation;
> magnification is another, and the low noise of big pixels is visually
> magnified when the pixels are magnified along with the subject.
Exactly, and if you don't need the extra pixels you can bin.
>
> I am quite certain that the only benefits of big pixels are:
>
> 1) quicker readout time and less storage requirements, and
>
> 2) slight benefit in photons collection rate per unit of sensor area due
> to less wasted space on the sensor (not always realized, however; my
> 1.97u FZ50, for example, collects about the same number of photons per
> unit of area as the 1DmkII, at RAW saturation for the same ISO).
Well, as long as there are no constant noise sources (eg 10 electrons/
pixel independent of the area). I have no idea if there are or not.
Pat
> I have to shoot action photos in low light conditions. What is the
> best DSLR for this purpose?
> Thanks,
> Yip
At the risk of pissing off all of the "purists" out there, you might
want to consider the original Canon Digital Rebel (the good old 300).
That would get you a useable body for not much money. Then add the
Russian operating system to get to ISO of 3200. It's a bit grainy but
sometimes grainy is better than nothing.
Then, with your "extra" money get a Canon 580 flash (or two) and a
"wedding bracket" to avoid red eye and limit shadow. Skip the kit
lens and get the Tokina F2 (or f2.8) zoom. it is something like a 28
to 70mm.
That would get you a servicable package within you price range.
There are lots of situation where this wouldn't be the right setup,
but for what you are describing it will work just fine.
Good luck with it.
Roger N. Clark (change username to rnclark)
> "Roger N. Clark (change username to rnclark)" <user...@qwest.net> wrote
> in news:45F577C0...@qwest.net:
>
>>I and other astrophotographers tend to ignore fixed pattern noise
>>because we can calibrate most of it out of our images.
>
> I'm not sure where "fixed pattern noise" came into play here; the issue
> was read noise and one of it's components, 1-D noise. There is, for all
> intents and purposes, zero fixed pattern noise in my 20D. Subtracting a
> stack of black frames from a short exposure results in nothing but
> slightly higher noise.
Fixed pattern noise occurs in different ways with different
sensors. All sensors have fixed pattern noise, even your
20D unless you have a magical one. For example, see:
http://www.astrosurf.org/buil/5d/test.htm
It is in French, but the pictures are labeled well enough
with 30D, 5D etc, that you can see the effects. Common
is vertical striping and amplifier glow. There is no camera,
CCD or CMOS that doesn't have fixed pattern noise.
Figure 10 at this page:
http://www.clarkvision.com/photoinfo/night.and.low.light.photography
shows that the Canon 1D Mark II has a low level background offset.
That too is fixed pattern noise. So is the line striping
you see in the images on this page. All cameras have these
effects.
A good example of amplifier glow creating an offset near the
edge of the frame is at:
http://www.clarkvision.com/imagedetail/long-exposure-comparisons
e.g. see Figure 2b.
>> If that is an
>>issue for other people, then I suggest they learn how to take
>>dark frames, average them, and subtract them from their images.
>
> What about the read noise in short exposures?
Read noise produces a random signal added to all
other signals, regardless of exposure. It is a property of
reading the sensor, not a property of the exposure time.
Examples on the above two web pages show read noise in both
short and long exposures.
>>It is really pretty easy, but for best results, it needs to be
>>done on linear data.
>
> And in the case of Canons which have "negative noise" at the blackpoint,
> it needs to be done without any clipping at the black level.
Sensors collect photons, which are converted to electrons.
The signal is always positive or zero, not negative.
The readout electronics add a negative offset
so that the signals do not go negative. Of course,
if noise is too high, then the output signal could hit
zero. Very few pixels are zero in most cameras, even
at the shortest exposure times in the dark.
(I know you know this; I'm adding information to provide
a complete story for others reading, so please don't take
offense; I know you have studied sensors in detail and you have
provided great information to us for years.)
So, I don't know what you mean by negative noise.
>>Another calibration that can improve images is
>>flat field calibration, which not only corrects for pixel to pixel
>>variations, but corrects for light fall-off from lenses.
>>But if someone wants to pay me to run more tests......
>
> I don't feel like financing anything right now, but I might suggest that
> when you have the time, you do a "gap" test of large vs small pixels.
> Your 1DmkII vs S70 page seems to be about pixel size, but it is really
> about sensor size. Do a test with a small-pixel camera, and the 1DmkII,
> both using the same real focal length, the same Av value, the same Tv
> value, the same ISO setting, of the same detailed subject from the same
> distance. I guarantee that your big pixels will fall to the ground like
> Goliath, when viewing the subject at any magnification, from both
> downsampled to both upsampled, or printed large. This is the real test
> of pixel size. What you seem to overlook in your analyses is the fact
> that standard deviation is only *one* factor in the noise equation;
> magnification is another, and the low noise of big pixels is visually
> magnified when the pixels are magnified along with the subject.
>
> I am quite certain that the only benefits of big pixels are:
>
> 1) quicker readout time and less storage requirements, and
>
> 2) slight benefit in photons collection rate per unit of sensor area due
> to less wasted space on the sensor (not always realized, however; my
> 1.97u FZ50, for example, collects about the same number of photons per
> unit of area as the 1DmkII, at RAW saturation for the same ISO).
Here is the fundamental fallacy of your assertion that the
only benefit is better fill factor (that is what you describe in
#2 above): The physics of lenses, and not directly related
to sensors at all.
Every lens at a given f/ratio delivers, for a given light source,
the same surface brightness in th4e focal plane. Another
way to put this is the photons per square micron is constant
at a given f/ratio regardless of the lens focal length.
So an f/4 lens of 20mm focal length looking at a gray
card in sunlight delivers the same number of photons per
square micron to its focal plane as does a 500 mm f/4 lens
looking at the same gray card. It is a simple deduction,
that given two sensors, identical in every way including
quantum efficiency, read noise, and fill factor, that
the sensor with larger pixels collects more photons
simply due to lens physics.
An 8 micron pixel collects 16 times the photons as a
pixel 2 microns in size (8*8/(2*2) = 16), and that is exactly
what we observe with today's digital cameras. For example,
see:
Digital Cameras: Does Pixel Size Matter?
Part 2: Example Images using Different Pixel Sizes
http://www.clarkvision.com/imagedetail/does.pixel.size.matter2
> Here is one of my tests; it needs to be redone, because I realized after
> doing it that ISO 1600 on the FZ50 is crippled by a very bad amplifier,
> that is worse than pushing 100 to 1600. Here is the original, however:
>
> http://www.pbase.com/jps_photo/image/74020772
>
> Don't forget that the 10D images would need to be sharpened more,
> sharpening the noise as well.
Your test is biased in that the two images from the two cameras
are not comparable. By using two different sized sensors
with the same focal length, of course the sensor with
smaller pixels sees finer detail. But the large sensor
shows a larger field of view that is not covered by the
smaller sensor at all. So depending on who wanted the
image, one could draw different conclusions: the person who
wanted a wide field of view would choose the large sensor;
one who wanted a telephoto image would choose the small
pixels. But in either case, the pixels from the small
sensor would be noisier in proportion to the square root
ratio of the areas of each pixel.
Roger
David J. Littleboy
"Roger N. Clark (change username to rnclark)" <user...@qwest.net> wrote:
I think you guys are talking past each other here.
I think John is arguing that _for a sensor of a given size_, larger pixels
aren't any better.
David J. Littleboy
Tokyo, Japan
Roger N. Clark (change username to rnclark)
> I think you guys are talking past each other here.
>
> I think John is arguing that _for a sensor of a given size_, larger pixels
> aren't any better.
1) Well, his example used 2 different sized sensors.
2) There is a difference. The signal you record has added
read noise. A larger pixel collects more photons
so the signal is larger compared to the read noise.
Thus you can detect fainter things, or have better high
ISO performance. If you sum the signal from a smaller
pixels to equal the area of a larger pixel size,
you are also adding read noise, so you don't gain
as much as having the larger pixel with one read noise.
Roger
acl
> I think you guys are talking past each other here.
>
> I think John is arguing that _for a sensor of a given size_, larger pixels
> aren't any better.
>
But doesn't this make him a "crop fan" for you? Or does your attitude
depend on who you're replying to?
acl
<usern...@qwest.net> wrote:
> 2) There is a difference. The signal you record has added
> read noise. A larger pixel collects more photons
> so the signal is larger compared to the read noise.
> Thus you can detect fainter things, or have better high
> ISO performance. If you sum the signal from a smaller
> pixels to equal the area of a larger pixel size,
> you are also adding read noise, so you don't gain
> as much as having the larger pixel with one read noise.
>
Is read noise fixed per pixel, per unit area, or something else?
Roger N. Clark (change username to rnclark)
Read noise is per pixel. Say you had 2 sensors, one with half
the pixel size, so you needed to add 4 pixels to equal the area
of the larger pixel. Lats say both had great read noise of
4 electrons. The larger pixel gets: X + 4 electrons noise.
The smaller pixel sensor, adding 4 pixels gets:
X + sqrt(4)*4 = X + 8, so the read noise is effectively
doubled.
Read noise for a given sensor is dependent on the design of the sensor
and how the readout is configured. Read ranges from just under 4
to about 30 electrons and is not dependent on pixel size.
For example, see Figure 3 at;
http://www.clarkvision.com/imagedetail/digital.sensor.performance.summary
At low ISO, and low bit count (e.g. 12 bits) and noise in the A/D converter
contributes greater noise than the true read noise from the sensor.
Roger
David J. Littleboy
"acl" <achilleas...@yahoo.co.uk> wrote:
> On Mar 16, 6:29 am, "David J. Littleboy" <davi...@gol.com> wrote:
>
>> I think you guys are talking past each other here.
>>
>> I think John is arguing that _for a sensor of a given size_, larger
>> pixels
>> aren't any better.
>
> But doesn't this make him a "crop fan" for you?
No. I think what John is saying is orthogonal to sensor size arguments. He's
arguing that for a given sensor size, one wants as many pixels as one can
get. Roger is arguing that for a given number of pixels, one wants the
largest sensor you can get.
I suspect that they're both right.