Good vs. Bad UV Haze filters?
Paul Ciszek
The author used a UV/Visible spectrophotometer to compare different
UV/Haze filters. It shows four filters doing no serious attenuation
down to 350nm (which was as far as their instrument would go). The
"B+W" UV filter looks the best to me, with a flat transmission curve
across the visible and abrupt absorption beginning in the high 300's;
I wish the article identified the "B+W" filter more specifically.
The Hoya filter looks to me like it would interfere with color balance
in the visible range.
Since I live in Colorado and will probably be taking most of my pictures
at high altitudes, a good UV filter is necessary. Has anyone here
compared different UV filters? My camera is a Lumix FZ35, which takes
46mm filters.
--
Please reply to: | "Any sufficiently advanced incompetence is
pciszek at panix dot com | indistinguishable from malice."
Autoreply is disabled |
J�rgen Exner
>Since I live in Colorado and will probably be taking most of my pictures
>at high altitudes, a good UV filter is necessary.
Actually I strongly doubt that UV-filters are of much use on digital
cameras at all. The sensors are painfully optimized for visible light
and not (or at the very least not overly) sensitive to UV light.
If at all you may want to adjust the white balance, but that should be
sufficient.
jue
Rich
> I came across this site:http://photo.net/equipment/filters/
> The author used a UV/Visible spectrophotometer to compare different
> UV/Haze filters. It shows four filters doing no serious attenuation
> down to 350nm (which was as far as their instrument would go). The
> "B+W" UV filter looks the best to me, with a flat transmission curve
> across the visible and abrupt absorption beginning in the high 300's;
> I wish the article identified the "B+W" filter more specifically.
> The Hoya filter looks to me like it would interfere with color balance
> in the visible range.
>
Unless you are completely paranoid about your lenses, or if you are
sure you are likely to damage the front element of a lens, UV filters
are a complete waste of time and a major problem where reflections are
concerned. Use a hood, forget the filter.
John Passaneau
In film photography the UV or haze filter was important because film was
more sensitive to UV than visible light. The first films used were only
sensitive to blue light. Later dyes were found that extended the
sensitivity down into the reds. On the other hand, solid state detectors
made of silicon are more sensitive to infrared light than UV. Almost all
digital cameras sensors have infrared filters over the sensors to reduce
this problem. I speculate that many of the lens that have been specially
designed for digital incorporates infrared filtering in there design
which would have the effect of improving the contrast of the lens. A UV
filter is not as necessary as it was in the past. But strong UV may
cause the glass in your lens to fluoresces giving a color tint over your
photo. There is strong debate over the value of a filter protecting the
front element of your lens is worth the trouble but all agree that in
very harsh environments it's a good thing to do. My suggestion it to try
a filter and see if it helps.
John Passaneau
Physics dept Penn State University
No spam please
news:4B435A4F...@arrl.net...
Hello folks.
I dropped a 24mm lens onto a carpeted floor. The UV filter was a write-off
but the lens itself was fine.
Bye for now,
R.
--- news://freenews.netfront.net/ - complaints: ne...@netfront.net ---
Ofnuts
> I dropped a 24mm lens onto a carpeted floor. The UV filter was a write-off
> but the lens itself was fine.
Nothing says the 24mm alone wouldn't have survived :-)
--
Bertrand
No spam please
news:4b43846a$0$689$426a...@news.free.fr...
The filter was a write off . If it hadn't been on the lens then the front of
the lens would have taken that impact.
It would have been a workshop repair or replace.
A zoom lens wasn't so lucky when I tripped on the pavement. It took an
impact to the body end of the lens. That was a workshop job; it needed a new
rear end tube.
Regards, R.
Ofnuts
> "Ofnuts"<o.f.n...@la.poste.net> wrote in message
> news:4b43846a$0$689$426a...@news.free.fr...
>> On 05/01/2010 17:32, No spam please wrote:
>>
>>> I dropped a 24mm lens onto a carpeted floor. The UV filter was a
>>> write-off
>>> but the lens itself was fine.
>>
>> Nothing says the 24mm alone wouldn't have survived :-)
>>
>> --
>> Bertrand
> Hello Bertrand.
>
> The filter was a write off . If it hadn't been on the lens then the front of
> the lens would have taken that impact.
> It would have been a workshop repair or replace.
>
> A zoom lens wasn't so lucky when I tripped on the pavement. It took an
> impact to the body end of the lens. That was a workshop job; it needed a new
> rear end tube.
>
Consider: naked lens falls on wood table corner: heavy and thick lens
harder than wood, no damage to lens. Lens with filter falls on wood
table corner: light and thin filter breaks to pieces, shards make
scratches on the lens. Hood is better.
--
Bertrand
John McWilliams
> "Ofnuts" <o.f.n...@la.poste.net> wrote in message
> news:4b43846a$0$689$426a...@news.free.fr...
>> On 05/01/2010 17:32, No spam please wrote:
>>
>>> I dropped a 24mm lens onto a carpeted floor. The UV filter was a
>>> write-off
>>> but the lens itself was fine.
>> Nothing says the 24mm alone wouldn't have survived :-)
>>
>> --
>> Bertrand
> Hello Bertrand.
>
> The filter was a write off . If it hadn't been on the lens then the front of
> the lens would have taken that impact.
Not usually. Most lenses have a lip around the front. True, if there was
a rock, say, that it impacted in the center, bye-bye lens.
> It would have been a workshop repair or replace.
>
> A zoom lens wasn't so lucky when I tripped on the pavement. It took an
> impact to the body end of the lens. That was a workshop job; it needed a new
> rear end tube.
There are some blows a lens can take that say big problem, and no filter
nor lens cap nor shade will help. I prefer just a solid lens shade. It
provides good protection/impact absorbing qualities that a rigid filter
cannot.
--
john mcwilliams
Rich
> On 05/01/2010 20:34, No spam please wrote:
>
>
>
There are some multicoatings now that are as hard as the glass itself
(5 on the MOH scale for crown glass) so they should stand up very well
to abuse. However, I don't know which if any camera companies are
using this material.
Paul Ciszek
according to this article do not attenuate UV much if at all:
http://photo.net/equipment/filters/
...with the transmission curve of soda-lime glass, aka ordinary window
glass:
http://www.sinclairmfg.com/datasheets/sodalimecurve.htm
It seems plausible to me that "Millenium UV", "Millenium Haze",
"Promaster UV", and "Tiffen UV Protector" are just ordinary window
glass, perhaps with some coatings.
Neil Harrington
I agree. I believe this whole business of "protective" filters started with
salesmen asking every new lens buyer, "You wanna filter to protect the
lens?" -- as if that were the purpose of a filter. I think a salesman asked
me that every single time I bought a lens, in the days before buying lenses
online became the easiest way to do it. Judging by the number of Skylight
and UV filters I've seen more or less permanently attached to lenses, I
guess this sales tactic must have usually been successful in pushing these
high-markup items.
In well over 50 years of amateur photography I have NEVER used a filter "to
protect the lens," though I have used them for their design purpose,
filtering. I've never yet had a lens damaged by lacking a "filter for
protection." I have seen some filters stuck so tightly to the lenses they
were put on they could not be removed (though dust managed to get inside the
filter), and on one occasion trying to remove a filter resulted in
unscrewing the whole front component of the lens.
Especially for lenses with the front element near the front of the lens, I
think a lens hood is the best protection.
MikeWhy
news:_-6dnU8SHdcA2NnW...@giganews.com...
> In well over 50 years of amateur photography I have NEVER used a filter
> "to protect the lens," though I have used them for their design purpose,
> filtering.
I would only add that the few times I wondered if a haze filter wouldn't
help cut through and improve contrast even marginally in the late afternoon
high altitude mountain haze, the said Tiffen Haze1 was more than 1000 miles
away, safely tucked in the lens drawer, forever unused. I might never know
firsthand if they really do anything useful. "Storing" it on the lens might
not be such a horrible idea, even though I confess to wondering if haze
filters weren't named for the lost of contrast they contribute the rest of
the time.
David J Taylor
Doug McDonald
> Compare the transmission curves of the four "deadbeat" filters that
> according to this article do not attenuate UV much if at all:
> http://photo.net/equipment/filters/
>
> ...with the transmission curve of soda-lime glass, aka ordinary window
> glass:
> http://www.sinclairmfg.com/datasheets/sodalimecurve.htm
>
> It seems plausible to me that "Millenium UV", "Millenium Haze",
> "Promaster UV", and "Tiffen UV Protector" are just ordinary window
> glass, perhaps with some coatings.
>
>
None of those, except the Hoya one, would have any effect at all on my
Canon 30D. I tested the sensor in it with monochromatic light
from 300-450 nm, and it was quite dead by 380 nm, and almost dead
at 400 nm. It was fairly equivalent, in fact, to the Hoya filter,
a little steeper.
Doug McDonald
Doug McDonald
> You may find these articles helpful:
>
> http://www.clarkvision.com/articles/evaluating_filter_quality/index.html
Indeed! On my Canon 70-300mm telephoto, at the long end
only the most expensive B+W polarizing filer did not degrade the image.
That expensive one, however, was just fine, even wide open.
Doug McDonald
Wolfgang Weisselberg
> I speculate that many of the lens that have been specially
> designed for digital incorporates infrared filtering in there design
> which would have the effect of improving the contrast of the lens.
A look into lists of what lenses are useful for IR photography
indicates your speculation is likely wrong: the most common
problems are IR hotspots --- and I haven't yet heard of a lens
that's opaque to IR, though such a beast may exist.
-Wolfgang
David Ruether
"Paul Ciszek" <nos...@nospam.com> wrote in message
news:hhtrab$bve$1...@reader1.panix.com...
> I came across this site: http://photo.net/equipment/filters/
> The author used a UV/Visible spectrophotometer to compare different
> UV/Haze filters. It shows four filters doing no serious attenuation
> down to 350nm (which was as far as their instrument would go). The
> "B+W" UV filter looks the best to me, with a flat transmission curve
> across the visible and abrupt absorption beginning in the high 300's;
> I wish the article identified the "B+W" filter more specifically.
> The Hoya filter looks to me like it would interfere with color balance
> in the visible range.
>
> Since I live in Colorado and will probably be taking most of my pictures
> at high altitudes, a good UV filter is necessary. Has anyone here
> compared different UV filters? My camera is a Lumix FZ35, which takes
> 46mm filters.
Even with transparency film, the effects of UV on images at
elevations to at least 11,000 feet are negligible - and any that
you may encounter with digitial can be removed later, or by
auto-white balance in the camera while shooting. Also, most
multi-element lenses themselves absorb quite a bit of UV. If
you want a good UV to just cover the lens with, I like the
Hoya single coated UV or clear filters - but I avoid Tiffen
filters "like the plague".
--DR
David Ruether
"MikeWhy" <boat042...@yahoo.com> wrote in message
news:hi1jbr$ohj$1...@news.eternal-september.org...
I had a job almost ruined by forgetting to clean my color correction
Tiffen filters before use (they tended to "self-fog" in less than 3 months
of storage on both sides, and always needed cleaning before use - and
none of my other filters had this problem, stored in the same cases...),
thus my low opinion of Tiffen filters. It may be that you saved yourself
from adding haze TO the photos - but I've never found a "haze" filter to
work as advertised in those advertising sample pictures! ;-) But, on the
other side, I do use good (Hoya and Nikkor) filters to keep lenses clean
(cleaning multicoated surfaces completely is very difficult, and I would
rather scrub a filter, which I can also wash, than a lens surface...). I
also use shades when they contribute (which is not always - and when
they don't, I prefer the simplicity and compactness of leaving them off).
BTW, I once had a wide angle grabbed, and the filter got scratched
badly in the process, so I prefer to use "protective" filters when possible.
Also, a friend sent me some samples from her new Panasonic FZ35
since she had been complaining about "white spots" in the images shot
against the light (and she insisted her lens was clean...). But, there was
the evidence in her images of spots on the lens - which would have been
FAR easier for her to see and to remove had they all been on a filter...
--DR
Paul Ciszek
In article <hhu11a$cge$1...@ruby.cit.cornell.edu>,
David Ruether <d_ru...@thotmail.com> wrote:
>
>Even with transparency film, the effects of UV on images at
>elevations to at least 11,000 feet are negligible - and any that
>you may encounter with digitial can be removed later, or by
>auto-white balance in the camera while shooting. Also, most
>multi-element lenses themselves absorb quite a bit of UV. If
>you want a good UV to just cover the lens with, I like the
>Hoya single coated UV or clear filters - but I avoid Tiffen
>filters "like the plague".
May I ask why? I was given a Tiffen filter with the camera.
rwalker
<d_ru...@thotmail.com> wrote:
snip
> But, on the
>other side, I do use good (Hoya and Nikkor) filters to keep lenses clean
>(cleaning multicoated surfaces completely is very difficult, and I would
>rather scrub a filter, which I can also wash, than a lens surface...)
snip
That is the primary reason I have UV filters on most of my lenses.
I've shot without and with the filters, and the difference is not
noticeable to me. And since I only shoot for me, that's all that
matters. And, as you say, I'd rather clean the filter than the
actual lens. I don't have any illusions that the filter is magically
going to protect the lens from breaking in a high impact accident.
Ray Fischer
>In well over 50 years of amateur photography I have NEVER used a filter "to
>protect the lens," though I have used them for their design purpose,
>filtering. I've never yet had a lens damaged by lacking a "filter for
>protection."
Bully for you. One trip to the beach on a windy day was enough to
convince me that filters are very useful protection.
Unless you _like_ the front of your lens coated with salt spray?
--
Ray Fischer
rfis...@sonic.net
Chris H
<rfis...@sonic.net> writes
It's not just the beach.... dusty locations such as the farms and rural
areas have wind blown dust in the air, this will "sand blast" the front
of a lens. These days cities are no cleaner
You only have to look at windows in buildings and cars to see the sort
of stuff that is in the air.
Mind you I have never found Neil to be actually connected to reality.
--
\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\
\/\/\/\/\ Chris Hills Staffs England /\/\/\/\/
\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/
No spam please
Hello Bertrand.
I agree about hoods and they're usually on my lenses when I am using them.
When the 24mm lens hit the carpet it was actually supposed to be on its way
into my gadget bag and the hood wad already been removed.
When a lens with a filter hits the table then the filter has the weight of
the lens behind it. In the specific case of my 24mm lens, the filter ring
hit the carpet and deformed. The filter glass was cracked due to the
deformation of that filter ring. Without the filter then it would have been
the lens's filter mount that would have deformed.
Of course, the best policy is never to drop a lens. Some of us are just a
bit too clumsy.
Regards,
Roger.
whisky-dave
"rwalker" <rwa...@despammed.com> wrote in message
news:etfak5lvh3gsfcp6v...@4ax.com...
I've always concidered the filter to be protection from dust and grime
but what I found strange was that some people/photographers didn;t consider
the
fact that cleaning a filter quickly i.e without care because it's cheap and
replaceable
will degrade the quality of the image. This was in the days of film.
So my thoughts were that if a filter gets scratched/damaged then it should
be changed
but I've rarely heard of people actully doing this and prefer to just keep
using the
'protective' and somewhat scoured filter.
Neil Harrington
"Chris H" <ch...@phaedsys.org> wrote in message
news:uqctcSEh...@phaedsys.demon.co.uk...
> In message <4b45577f$0$1663$742e...@news.sonic.net>, Ray Fischer
> <rfis...@sonic.net> writes
>>Neil Harrington <ne...@home.com> wrote:
>>>In well over 50 years of amateur photography I have NEVER used a filter
>>>"to
>>>protect the lens," though I have used them for their design purpose,
>>>filtering. I've never yet had a lens damaged by lacking a "filter for
>>>protection."
>>
>>Bully for you. One trip to the beach on a windy day was enough to
>>convince me that filters are very useful protection.
>>
>>Unless you _like_ the front of your lens coated with salt spray?
>
>
> It's not just the beach.... dusty locations such as the farms and rural
> areas have wind blown dust in the air, this will "sand blast" the front
> of a lens. These days cities are no cleaner
>
> You only have to look at windows in buildings and cars to see the sort
> of stuff that is in the air.
>
> Mind you I have never found Neil to be actually connected to reality.
You and Fischer make a perfect pair. Sort of a match made in heaven.
By all means use a filter to prevent all that "sand blasting." In fact you
should put another filter on top of that one to protect it from sand
blasting too. Maybe stack two or three more on there just to be on the safe
side.
<guffaw!>
David Ruether
>>Even with transparency film, the effects of UV on images at
>>elevations to at least 11,000 feet are negligible - and any that
>>you may encounter with digitial can be removed later, or by
>>auto-white balance in the camera while shooting. Also, most
>>multi-element lenses themselves absorb quite a bit of UV. If
>>you want a good UV to just cover the lens with, I like the
>>Hoya single coated UV or clear filters - but I avoid Tiffen
>>filters "like the plague".
> May I ask why? I was given a Tiffen filter with the camera.
The answer is in another post of mine, below - but briefly,
they appear to be uncoated, and they "self-fog" over short
periods of time and therefore require cleaning (on both sides)
before use, plus the rims are thick, which can cause vignetting
with some lenses at some settings. "Bottom of the barrel" quality,
but they do have one plus that makes them desirable to some
professionals, especially motion-film cameramen - Tiffen offers
a wide range of colors in thread-mount glass filters... (but
otherwise, YUCK!).
--DR
David Ruether
I have also made comparisons of lens performance with/without
UV filters (including using a 400mm f3.5 on a good distant subject
with multiple refocus exposures for accuracy, with no filter, only the
rear UV, only the front UV, and with both UV filters in place - with
no differences noted). I also don't find multicoating on filters very
useful. The exception to the above can happen when shooting nearly
directly toward a relatively very bright and smallish light source, when
a reflection off the sensor/film may be bounced back to the front filter,
and then imaged again, but.........;-)
--DR
David Ruether
"whisky-dave" <whisk...@final.front.ear> wrote in message news:hi4rvf$99e$1@qmul...
8^) And, remember the days when "pros" used to "clean" their lenses
with quick swirls of their neckties on them? Those lenses were soon
good for little more than taking "moody portraits"... :-( I agree that
anyone concerned about optimizing the performance of their gear
should examine it and replace it as needed - but it is surprising how
many *barely visible* scratches an optical surface can have without
impairing its optical qualities.
--DR
Neil Harrington
"David Ruether" <d_ru...@thotmail.com> wrote in message
news:hi547g$1rq$1...@ruby.cit.cornell.edu...
A local studio photographer about 50 years ago told me he left a lens
uncapped on a shelf to soften it for portraiture by acquiring dust. It
seemed to me a rather haphazard method, but evidently it worked all right
for him.
> I agree that
> anyone concerned about optimizing the performance of their gear
> should examine it and replace it as needed - but it is surprising how
> many *barely visible* scratches an optical surface can have without
> impairing its optical qualities.
Not in my personal experience, but I have read that even a fairly deep
scratch is unlikely to make any visible difference in imaging. And some used
to say that a bubble in the glass was the "sign of a good lens." That's
probably a silly notion, but my guess is that many years ago bubbles in
optical glass were not rare and if reasonably small probably did not
substantially affect image quality. About 45 years ago I had a Piesker 85mm
f/2 with a small bubble in a front element, but that's the only bubble I
ever saw in a lens.
jean-daniel dodin
> Not in my personal experience, but I have read that even a fairly deep
> scratch is unlikely to make any visible difference in imaging.
urban legend... may be related to the focal length.
put a hair on the lens of a smartphone, you can see it (or it's
shadow). Try the same on a better lens with different aperture. after
all, experimenting is easy with digital cameras
jdd
--
http://www.dodin.net
Le wiki des forums son-image franï¿œais:
http://new.dodin.org/frsv/
http://valerie.dodin.org
David Ruether
"jean-daniel dodin" <j...@dodin.org> wrote in message
news:4b4621d7$0$29883$426a...@news.free.fr...
> Le 07/01/2010 18:45, Neil Harrington a �crit :
>> Not in my personal experience, but I have read that even a fairly deep
>> scratch is unlikely to make any visible difference in imaging.
> urban legend... may be related to the focal length.
Yes. A relatively long focal length lens with a relatively large
sensor area would probably show little or no ill effect from
a fairly deep scratch even at a smallish stop with textured
subject material - but with a good WA converter on a good
1/3rd" CCD video camera set at WA, even the tiniest, barely
visible pin-prick sized "tick" in the front element glass can
show in side and back lighting conditions.
> put a hair on the lens of a smartphone, you can see it (or it's
> shadow). Try the same on a better lens with different aperture. after
> all, experimenting is easy with digital cameras
>
> jdd
Yes - this is one of the downsides of compact cameras. Even
a friend's Panasonic FZ35 had spoiled pictures likely resulting
from "spit marks" or condensation on the front element that
were difficult to see.
--DR
Paul Ciszek
In article <4b45577f$0$1663$742e...@news.sonic.net>,
Even before this discussion, I was playing with the follwoing idea:
If you placed a sapphire (Al2O3) window between your lenses and the cruel
world, and coated the *inside* of the window with a MgF coating, you
would have an outside surface harder than anything except diamond,
that would be very difficult to scratch and easy to clean, and an
inner surface with near-perfect anti-reflection. You would lose 6%
of your light from reflection off of the outside surface, though.
Chris Malcolm
> Le 07/01/2010 18:45, Neil Harrington a ?crit :
>> Not in my personal experience, but I have read that even a fairly deep
>> scratch is unlikely to make any visible difference in imaging.
> urban legend... may be related to the focal length.
> put a hair on the lens of a smartphone, you can see it (or it's
> shadow). Try the same on a better lens with different aperture. after
> all, experimenting is easy with digital cameras
It's not urban legend, and it's got nothing to do with "better". It's
the simple basic optics of aperture physical size and depth of
field. At f/2.8 at 50mm on a APS-C sized sensor I can photograph
through thick wire netting which becomes completely invisible if it's
less than about two inches from the lens. It so happens that to get a
lens and image sensor of that size you probably have to buy a better
camera, but the quality has nothing to do with the swallowing of
obstructions close to the lens in depth of field. That's just the
basic optics, and would work with a really cheap crappy film camera of
the same dimensions.
--
Chris Malcolm
melanie jones
> harder than wood, no damage to lens. Lens with filter falls on wood table
> corner: light and thin filter breaks to pieces, shards make scratches on
> the lens. Hood is better.
>
> --
> Bertrand
I agree and disagree. Last year I dropped a lens with a filter, the filter
broke and hundreds of particals of glass stuck to the lens. Some of the
small particles of glass seemed to be invisible, and over a few months they
would reappear all over the lens, beneath my replacement uv filter. In the
end I scratched the lens itself whilst trying to clean up residual glass
particals.
However, this evening I disovered some totally uncleanable smudges on
another uv filter. It was just impossible to clean with a cloth or a lens
cleaning solution. Out if desperation I dipped it in acetone for 10 seconds
and to my amazement the lens did not dissolve and the dirt came off. On
this occasion I was glad that I had the filter on the lens.
jean-daniel dodin
> field. At f/2.8 at 50mm on a APS-C sized sensor I can photograph
> camera, but the quality has nothing to do with the swallowing of
> obstructions close to the lens in depth of field. That's just the
> basic optics, and would work with a really cheap crappy film camera of
> the same dimensions.
>
quality is not only for big aperture. It's for any use
whisky-dave
>
>> Not in my personal experience, but I have read that even a fairly deep
>> scratch is unlikely to make any visible difference in imaging.
>
> urban legend... may be related to the focal length.
Or rather DOF.
So suppose you have a 3mm human hair (pubic or not).
Would it be more noticable if it were on the filter or on the front element
of the lens,
and would that depend on the focal length of the lens.
Then consider the focusing point I assume if it were infinity it'd be less
noticeable
than if the lens was focused at 1/2 metre.
So if you have the same fault on a filter or the lens which is worse for
image quality.
i.e is it better to have the same size scratch on a filter or the lens from
the POV of image
quality rather than replacement costs.
>
> put a hair on the lens of a smartphone, you can see it (or it's
> shadow).
Some of the 'optics' I've seen on smart phones a human hair is almost a lens
cap ;-)
>Try the same on a better lens with different aperture. after
> all, experimenting is easy with digital cameras.
My other point is at which point do you decide to throw the protective
filter in the bin
because it's too damaged and is degrading your images.
Outing Trolls is FUN!
wrote:
All bullshit. A common idiot's tale told and passed down on the net by
pretend-photographers. A lens can even have some bubbles in the glass and
still perform admirably. Any large scratches in any filter can be
blacked-out with a sharpie with no perceivable performance lost. One of my
favorites for Fall photography is an antique filter I found in a junk-box
one time. I cannot find a filter today with the same band-pass profile. A
large conchoidal fracture on one edge and several large scratches in it.
All defects blacked out with a sharpie and it performs admirably.
A large research-telescope mirror was shot at with a high-powered rifle by
someone with an unstable agenda and left huge divots in the mirror. They
were patched over and blacked out, with hardly any performance lost.
(Perhaps someone can find that link to show these idiots they are idiots.)
Stop parroting net-nonsense invented by armchair-photographer trolls.
Outing Trolls is FUN!
wrote:
>
>"jean-daniel dodin" <j...@dodin.org> wrote in message
>news:4b4621d7$0$29883$426a...@news.free.fr...
>> Le 07/01/2010 18:45, Neil Harrington a �crit :
>
>>> Not in my personal experience, but I have read that even a fairly deep
>>> scratch is unlikely to make any visible difference in imaging.
>
>> urban legend... may be related to the focal length.
>
>Yes. A relatively long focal length lens with a relatively large
>sensor area would probably show little or no ill effect from
>a fairly deep scratch even at a smallish stop with textured
>subject material - but with a good WA converter on a good
>1/3rd" CCD video camera set at WA, even the tiniest, barely
>visible pin-prick sized "tick" in the front element glass can
>show in side and back lighting conditions.
That's because at wide-angle everything from the front lens surface to
infinity is in focus you idiots. I have a fish-eye lens where I have to
keep the front of it in pristine condition or it will put any dust on that
lens in focus. This is NOT true for the average focal-lengths that all
others use, nor any filters placed in front of those lenses.
Outing Trolls is FUN!
Keep a good black magic-marker in your camera kit. When shooting through a
chain-link fence or other mesh-like obstruction (provided I have not found
a way to get around it temporarily) I just black-out the small portion I am
shooting through and can use almost any aperture.
Outing Trolls is FUN!
wrote:
>I also don't find multicoating on filters very
>useful.
Yes, armchair photographer trolls wouldn't.
David Ruether
"Outing Trolls is FUN!" <ot...@trollouters.org> wrote in message
news:sk3gk518841r5i3b9...@4ax.com...
Your response is inappropriate - and inaccurate. It is all relative,
as I (and others) pointed out. Example: while the video camera
example I gave is true, an 8mm (or even 6mm) fisheye lens on a
35mm camera does not show similar image problems with dust
or minor defects on its front surface. The likely reason is that DOF
is less with the larger "sensor", and the front element is relatively
huge compared with the area of the dust or defect. A wide angle
for a sheet film camera will unlikely ever show ill effects from dust
or defects unless either is extreme. Also a factor is the lighting,
as I pointed out. With front lighting and textured subject matter,
it is less likely that lens defects will be seen in the image than if the
lens itself is side-lit and the subject is smooth and dark. Properly
shading the lens surface may reduce or remove this effect, though.
Be careful who you call "idiots". The term may easily be thrown
back at you, especially if you oversimplify...;-)
--DR
David Ruether
>>... And, remember the days when "pros" used to "clean" their lenses
>>with quick swirls of their neckties on them? Those lenses were soon
>>good for little more than taking "moody portraits"... :-( I agree that
>>anyone concerned about optimizing the performance of their gear
>>should examine it and replace it as needed - but it is surprising how
>>many *barely visible* scratches an optical surface can have without
>>impairing its optical qualities.
>>--DR
> All bullshit. A common idiot's tale told and passed down on the net by
> pretend-photographers. A lens can even have some bubbles in the glass and
> still perform admirably. Any large scratches in any filter can be
> blacked-out with a sharpie with no perceivable performance lost. One of my
> favorites for Fall photography is an antique filter I found in a junk-box
> one time. I cannot find a filter today with the same band-pass profile. A
> large conchoidal fracture on one edge and several large scratches in it.
> All defects blacked out with a sharpie and it performs admirably.
>
> A large research-telescope mirror was shot at with a high-powered rifle by
> someone with an unstable agenda and left huge divots in the mirror. They
> were patched over and blacked out, with hardly any performance lost.
> (Perhaps someone can find that link to show these idiots they are idiots.)
>
> Stop parroting net-nonsense invented by armchair-photographer trolls.
Well, you are looking more and more like one of those.... I do remember
when photographers shot with 4x5 Graflexes, and wiped their lenses with
neckties - and I did see the fronts of their uncoated lenses (with soft glass)
turned into what was approaching diffusing surfaces (I bought and sold
gear, and I early on I learned to avoid gear if the seller mentioned being a
"pro" ["mint condition" to them meant that the gear sorta worked even if
it looked a mess] or if his voice sounded old [they unfortunately tended to
remember only what the gear was like when it was nearly new...]). BTW,
nothing in your post substantiates your description of what I, or anyone
else, has written as "all bullshit". But, put some of those "fixed" or "special"
filters you have described on a wide angle lens on a suitably sensitive
format size and try to shoot with it - yuh, just try...! ;-) Look who is really
writing mostly BS (and you know you are, which is really, really odd...! ;-).
(But I guess I'm just feeding the troll with the above, so, "BUH-BYE"! ;-)
--DR
John McWilliams
.
> (But I guess I'm just feeding the troll with the above, so, "BUH-BYE"! ;-)
Easy enough to do at first. But the more we resist, the less he'll persist.
--
john mcwilliams
David Ruether
"John McWilliams" <jp...@comcast.net> wrote in message
news:hia8ds$qck$1...@news.eternal-september.org...
> David Ruether wrote:
>> (But I guess I'm just feeding the troll with the above, so, "BUH-BYE"! ;-)
> Easy enough to do at first. But the more we resist, the less he'll persist. --
> john mcwilliams
Yes, of course - but it took me a while to spot him, sigh...! ;-)
I guess the name-calling should have been the give-away, though.
--DR