How to use bracketing exposures
carp
- black to white; parts of my picture are burned out or underexposed.
My Canon 10D allows bracketing, so that when the shot fires, I will
also have exposures 3 stops up and down from where I set the exposure.
My problems/questions are:
1) Which bracketing option setting should I use on the camera?
2) Once I have the several images in Photoshop, (lets say three: one a
little over, another underexposed and the third ok in most parts) how
do I go about cherry picking the best parts of each image and then
combining them into a single, perfectly exposed 4th image?
3) Do you use this bracketing technique much? Now with larger memory
sticks it is a lot more feasible.
carp
trouble
digital sensors, let alone film.
If you are taking stationary images on a tripod with a fixed aperture and
varied shutter speeds you need to learn about HDR processing.
The simplest and probably best program is not Photoshop but Photomatix. HDR
processing in Photoshop is difficult and rarely successful as opposed to
Photomatix which makes it easy to achieve reasonable results.
If you are simply bracketing hand-held shots you need to realize the limited
dynamic range of the sensor, expose for the brightest tone in which you want
to preserve detail and shoot raw.
There are many tricks to processing raw images that allow you to create
images which appear to have a larger effective dynamic range than they
actually do but you cannot learn those techniques from a newsgroup. There
are many sources for information about raw processing in Photoshop.
Paul Furman
> I often take shots with a (technical term please :) wide range of tone
> - black to white; parts of my picture are burned out or underexposed.
Dynamic range. Always a frustration with photography as we get so much
more out of our eyes than any camera can.
> My Canon 10D allows bracketing, so that when the shot fires, I will
> also have exposures 3 stops up and down from where I set the exposure.
>
> My problems/questions are:
>
> 1) Which bracketing option setting should I use on the camera?
> 2) Once I have the several images in Photoshop, (lets say three: one a
> little over, another underexposed and the third ok in most parts) how
> do I go about cherry picking the best parts of each image and then
> combining them into a single, perfectly exposed 4th image?
> 3) Do you use this bracketing technique much? Now with larger memory
> sticks it is a lot more feasible.
HDR (High Dynamic Range).
First, I understand most bracketing modes don't vary enough to be all
that useful for later merging with HRD software. The original intent of
bracketing was to get a little variation so you could pick the best &
throw the rest out. That's obsolete now but the function hasn't changed
yet to be useful. I never really bothered, I do it manually with
exposure compensation when I see the need, particularly after looking at
the histogram.
Second, when needed, I just take two exposures & combine them manually
in layers with a big soft eraser tool to do the masking in my editing
program rather than use the automated HDR programs. Experiment & use
undo/redo to check whether it really helped.
Thirdly, you can do local adjustments in software to duplicate much of
this effect if you aren't super picky. Even more if you shoot raw format.
--
Paul Furman
www.edgehill.net
www.baynatives.com
all google groups messages filtered due to spam
Toby
sufficient. Make sure that the darkest image has no blown highlights
anywhere. The three exposures must be in register and there must be nothing
moving between them, except very small details, or you will get serious
ghosting. A tripod is a must. You should set the camera to aperture priority
so that the depth of field does not change between shots.
After you have your exposures you need to create a 48 bit radiance file. In
Photoshop you can use the "merge to HDR" command. Once this file is created
you need to "tone map" the file to most effectively exploit the dynamic
range of the original exposures.
Photoshop generally does a very good job of creating the radiance file as
compared to any of the third-party HDR programs (Artizen, Photomatix and
EasyHDR Pro). It is quick, and it has good algorithms for aligning shots
when there is slight camera movement between them. It is not good at tone
mapping, and for doing this you should consider one of the above programs.
I've tried them all and I recomment EasyHDR Pro. It has the most control.
Photomatix is very good also, and actually if you are looking to create a
graphic rather than photorealistic effect it is better than any of the
others. Artizen seems easy but limited.
A final note: of all of the above only EasyHDR Pro creates decent radiance
files when there are very bright areas. I have a number of HDR images that
include the setting sun, for instance, and with all of the other proggies,
including Photoshop, the brightest areas are blown and posterized. EasyHDR
has never failed me, but all the rest create worthless files. The trouble is
that of all of them EasyHDR is the worst at lining up uneven edges or moving
objects.
FWIW,
Toby
"trouble" <fac...@hotmail.com> schrieb im Newsbeitrag
news:4R0nl.20717$Ws1....@nlpi064.nbdc.sbc.com...
bugbear
> After you have your exposures you need to create a 48 bit radiance file. In
> Photoshop you can use the "merge to HDR" command. Once this file is created
> you need to "tone map" the file to most effectively exploit the dynamic
> range of the original exposures.
Not always - you *can* go straight from bracketed
shots to a final output.
http://wiki.panotools.org/Enfuse
BugBear
whisky-dave
"carp" <yee...@gmail.com> wrote in message
news:e5d87bab-f5e0-4152...@t13g2000yqc.googlegroups.com...
I've tried it a few times, and I plan to again but mainly for special effect
stuff like water moving due to exposure lenghts.
You might find this articale interesting, I did until i saw the cost of the
gradualted
ND filers $199.
BTW the G10 as a 3 stop ND filter, althouhg I'm not sure exactly what use it
has
for HDR work niot much I'm guessing.
whisky-dave
"whisky-dave" <whisk...@final.front.ear> wrote in message
news:gnjkc7$auq$1@qmul...
>
Forgettign to add the link...
http://singhray.blogspot.com/2006/12/close-look-at-high-dynamic-range-hdr.html
Don Stauffer
There is a difference between bracketing and HDR photography. It sounds
like you are trying to combine the two.
Bracketing makes small changes in exposure, assuming you are somewhere
near the right exposure to start with. You do not combine the images,
you merely select the best to work further with. It is used for normal
scenes where camera can capture the entire range, but you just need to
optimize the exposure.
With HDR you make several shots ON A TRIPOD with a wider range of
exposures than in bracketing. Software then combines the shots, and
cranks down the contrast of the result so it will all print. PS, PSP
have such subprograms, or you can find standalone software to do HDR. It
is used for scenes with a VERY wide dynamic range, beyond capability of
the camera to capture.
carp
compositions; what about when everything is in motion and there is no
opportunity to use a tripod? Is it then that bracketing comes into its
own?
J. Clarke
<snip>
>
> With HDR you make several shots ON A TRIPOD with a wider range of
> exposures than in bracketing. Software then combines the shots, and
> cranks down the contrast of the result so it will all print. PS, PSP
> have such subprograms, or you can find standalone software to do HDR. It
> is used for scenes with a VERY wide dynamic range, beyond capability of
> the camera to capture.
Where is it written that one MUST use a tripod? How does setting
autobracket to the appropriate range then zipping off however many shots
on high speed drive preclude HDR?
whisky-dave
Tripod and several shots would be perfect for still life/studio
compositions; what about when everything is in motion and there is no
opportunity to use a tripod? Is it then that bracketing comes into its
own?
I wouldn't have thought so, that's probably when bracketing would be at it's
worse.
Don Stauffer
> Tripod and several shots would be perfect for still life/studio
> compositions; what about when everything is in motion and there is no
> opportunity to use a tripod? Is it then that bracketing comes into its
> own?
>
>
even on a tripod. But, I have also used camera automated bracketing
even on tripod. Lazy form of bracketing as opposed to doing it
manually. But that is okay. I am becoming more and more accepting of
automation in cameras, though I frequently manual focus, 'cause in
closeup work the cameras don't yet seem smart enough to pick the right
plane of best focus.
bugbear
> Bracketing does not necessarily use camera automation. One brackets
> even on a tripod. But, I have also used camera automated bracketing
> even on tripod. Lazy form of bracketing as opposed to doing it
> manually.
When taking bracketed shots for HDR, automatic bracketing
reduces the chance of nudgeing the camera/tripod
hard enough to mis align the shots.
BugBear
bugbear
> In message news:DIednURt9rsXWwPU...@posted.plusnet, bugbear
>
> 1. Set camera for raw image capture. (I will batch process later on so
> that post-processing is uniform).
> 2. Set camera for Aperture priority AE.
> 3. Set camera to manual focus.
> 4. Setup bracketing for 5 exposures, 1 stop apart.
> 5. Set camera to Mirror Lock Up.
> 6. Attach Phottix programmable cable release.
> 7. Program Phottix to fire shutter 10 times (5 for MLU, 5 to take
> picture), 4 seconds apart (so that vibration subsides after MLU.
>
CHDK is cheaper, and I don't get mirror vibration
on a non SLR (Canon A630)
SLRs have other advantages , of course.
BugBear
mortman
all. My Canon 20D, handheld,provides the sequence of 3 shots needed. The
program easily realigns the pictures automatically, and does a wonderful
job of combining the best features of each. The program is MUCH cheaper
than Photoshop and has a very short learning curve. Also, there are a
load of tutorials available on line.