recovering highlights from RAW for 20D/350D


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wind30

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Hi People,

I am thinking of getting my DSLR next month. Deciding between a s3pro and 20D. The main advantage for the s3pro for me is the highlight recovery using RAW.

I have laid hands on a s3pro for a short while and shot some sample shots. The below is RAW file devloped in ACR. orig exposure and pushed -4 stops.

orig
http://pisduck.com/s3pro/s3c.jpg
-4 stops
http://pisduck.com/s3pro/s3d.jpg

How good is the 20D highlight recovery from raw files? Basically, I shoot mainly just travel shots with my wife and many times I encounter blown out skies sometimes the sun is just at the wrong position of the sky. I was hoping my new camera can fixed it. I like the 20D for its ISO performance and the availablity of f4 L lens so I am wondering how its dynamic range is at ISO100.

I am hoping that even with -4 stops compensation at adobe raw, I can still have smooth color graduations and ACCURATE color.
 

shinken

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My personal experience for highlight recovery of the 20D: 1-2 stops at optimal. 2 stops plus possible. 3 stops - 4 stops... I've never tried it successfully. Although I didn't try it all that much. I've tried 3 - 4 stops for the 5D though.

Btw, have you considered the raw file sizes of the S3Pro? If my memory serve me correctly, they are quite substantially larger, which probably explains why it could do 4 stops comfortably.
 

gryphon

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Thats right.
Definately S3pro's dynamic range is better than the 20D. I heard the ISO is also equivalent, if not, even better than 20D.
The RAW size is 24MB each file:bigeyes: & the buffer is not that fast (can burst yr shoots) So if you are a very frequent RAW shooter, either stay away from it or buy more CF cards.

BTW you can get more details from Joho, he is selling his minty S3Pro as he shoots RAW and cannot handle the huge file size.
 

freelancer

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Apr 30, 2004
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wind30 said:
Basically, I shoot mainly just travel shots with my wife and many times I encounter blown out skies sometimes the sun is just at the wrong position of the sky.
If this is your main purchasing criteria, you would probably need some negative 1.0 to 1.5 EV correction during RAW conversion (speaking from a 20D with a 17-40 as a travel lens experiences). However I think that is not the issue as you will find the subject becoming much darker once you pull back on the EV. There is a technique called Digital Blending where you can get 2 TIFF files out of the same RAW file - one processed for highlights and one for shadows to increase the image dynamic range (which is really where the issue is I think). Or you can use CS2 HDR feature to do this if you brackett enough RAW shots.

Or you can meter for the sky and use fill flash for the subject.

Note that film has a better dynamic range (9 stops) than digital (around 6 to 7 stops) and this is a limitation of today's sensor technology.
 

wind30

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thanks for all the replies.

I know the limitations of s3pro (I owned it for a week) and thus I am wondering how close the dynamic range for the 20D is. If it is close enough, I really don't want to get a new s3pro with its 25meg raw file.

And for the s3pro ISO performance, my opinon from developing from ACR with ZERO noise reduction is that it is not that fantastic. But the out of camera jpegs are pretty good at ISO800 but it loses a LOT of detail at ISO1600. From the 20D samples, I think 20D is still better.

I know how to blend in CS2 using layers and masks. I don't really like the HDR feature as it requires multiple exposures. Any movement due to wind, camera shake results in a blur picture. And the automatic blending gives you are rather flat image.

So I guess the concensus for 20D is that it can go around -2 stops well. Have ANYONE tried -4 stops with 20D? The s3pro can go to -4 stops. So that is around 2 stops.
 

freelancer

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wind30 said:
So I guess the concensus for 20D is that it can go around -2 stops well. Have ANYONE tried -4 stops with 20D? The s3pro can go to -4 stops. So that is around 2 stops.
The other point I should mention is that when you push past 1.0 EV noise starts to show particularly in the shadow areas. It is always recommended to nail the exposure right in the camera - for example using ISO1600 correct exposure versus ISO800 and underexposing. The ISO1600 shots will be much cleaner in comparison.
 

wind30

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freelancer said:
The other point I should mention is that when you push past 1.0 EV noise starts to show particularly in the shadow areas. It is always recommended to nail the exposure right in the camera - for example using ISO1600 correct exposure versus ISO800 and underexposing. The ISO1600 shots will be much cleaner in comparison.
but usually you blend in two copies, one exposed for highlights (-3 stops) one for shadow (normal). The shadow areas in the highlight copy gets masked out.
 

wind30

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do you have the before blend files?

here is an example of the blending technique I picked up from luminous landscape. The picture is a test shot and as you can see, there is a HUGE difference between the shadow region and the highlight.

I basically use the highlight picture as a mask for the shadow picture. So no need to use brush (within one minute of work) and the result is more contrasty, ie the highlight picture does not darken the shadow areas.

http://forums.clubsnap.org/showthread.php?t=176655
 

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