A-Series RAW – Dynamic Range Test

[Graystar]

(NOTE: Sometimes my server is busy and you won’t get images. Just refresh after a few seconds.)

After being told that RAW isn’t about resolution detail but about dynamic range, I decided to test it.

The first image is a flash shot of the scene to show the colors and everything in it. Spot meter readings put the dynamic range of the scene at just over 8 stops. My A710 only has 6-7 stops of dr, so this scene was clearly beyond the ability of the camera, and it sure did show in the histogram.

The second image is the JPEG from the camera. Clearly loaded with blown and under-exposed sections.

The third image is the processed JPEG. Some recovery of detail was possible, but color detail had been lost and was unrecoverable. Histogram indicated posterization was beginning to form.

The fourth image is the RAW from the camera. Like the JPEG, it also had obvious over and under exposed sections, but not as bad.

The fifth image is the processed RAW. I was able to recover much detail and color, and was able to create an image that was close to what the eye sees.

I must say, I find the results fairly striking. And I’m sure that with more practice I could make the image even better. With this kind of ability I can see why some people feel that RAW is the only way to go. I’ve pretty much have decide that any important image has to be processed in RAW, and leave JPEG for the everyday stuff.

Scene lit by flash



JPEG from the camera.



JPEG processed.



RAW from the camera.



RAW processed.

 

[castaneda363]

Hi, i've also a A710.
I would like to know which software have you used to process RAW Image?

 

[Fredy Ross]

Me too.
--
fredyr

 

[Graystar]

Hi, i've also a A710.
I would like to know which software have you used to process RAW
Image?

I first used DNG for PowerShot 1.1.4 to convert the RAW file from the HDK firmware hack into an Adobe DNG file.

Then I edited the DNG file in Photoshop Elements.

Raw Therapee will open the RAW file directly and allow you to edit it.

DNG for PowerShot
http://www.zshare.net/download/dng4ps_1-1-4d-setup-exe.html

 

[castaneda363]

Hi, i've also a A710.
I would like to know which software have you used to process RAW
Image?

I first used DNG for PowerShot 1.1.4 to convert the RAW file from
the HDK firmware hack into an Adobe DNG file.

Then I edited the DNG file in Photoshop Elements.

Raw Therapee will open the RAW file directly and allow you to edit it.

DNG for PowerShot
http://www.zshare.net/download/dng4ps_1-1-4d-setup-exe.html

I have used RAWTherapy, but colors are differentent from Jpeg, i have also used DNG and after photoshop cs2 but i must set Auto for White Balance. I think because there is not a Color Profile for A710.
Someone Know how solves this problem?

 

[baloo_buc]

Use the temperature and green adjustments according to the rules (the light bulb is about 2700-3000 K, daylight 5500-6500 K, Shade and cloudy 7000-8500 K.

Auto it's not the best way to find the white balance. RAW is more work than JPEG but the results are rewarding. Also the sharpening and contrast should be done in RAW. Noise reduction is better also in RAW.
--
Victor
Bucuresti, Romania
http://s106.photobucket.com/albums/m268/victor_petcu/

 

[Graystar]

You are correct that the RAW file doesn't contain any camera info. You can use DNG for PowerShot to recover that information from the JPEG.

You need to download ExifTool and put it in the DNG For PowerShot 1.1\bin directory in Program Files. Then when you use DNG for PowerShot you can select the “Add metadata from jpeg” option.

http://www.sno.phy.queensu.ca/~phil/exiftool/

 

[castaneda363]

You are correct that the RAW file doesn't contain any camera info.
You can use DNG for PowerShot to recover that information from the
JPEG.

You need to download ExifTool and put it in the DNG For PowerShot
1.1\bin directory in Program Files. Then when you use DNG for
PowerShot you can select the “Add metadata from jpeg” option.

http://www.sno.phy.queensu.ca/~phil/exiftool/

I've put ExifTool into bin directory but when I click "add metadata from Jpg" it says "ExifTool.exe not found".
It's very strange, i don't know how to solve this problem......

 

[baloo_buc]

Use Exifer. It's like an image browser and you can manipulate EXIF very easily. Exiftools is great but it's still a command line program.
--
Victor
Bucuresti, Romania
http://s106.photobucket.com/albums/m268/victor_petcu/

 

[DazeMae]

GrayStar's instructions should work. When you extracted the orginal exiftool zip file, you should have gotten a file, exiftool(-k).exe. Rename this file, exiftool.exe and put it in DNG for PowerShot's bin subdirectory. Then, when running DNG for PowerShop, check the add metadata from jpeg option and it should work.

My guess is that you didn't rename the exiftool(-k).exe file.

 

[baloo_buc]

This is also a cause. I prefer copying the data in the final JPEG. Maybe the EXIF will automate a little bit the RAW processing.
--
Victor
Bucuresti, Romania
http://s106.photobucket.com/albums/m268/victor_petcu/

 

[castaneda363]

GrayStar's instructions should work. When you extracted the
orginal exiftool zip file, you should have gotten a file,
exiftool(-k).exe. Rename this file, exiftool.exe and put it in DNG
for PowerShot's bin subdirectory. Then, when running DNG for
PowerShop, check the add metadata from jpeg option and it should
work.

My guess is that you didn't rename the exiftool(-k).exe file.

I've renamed the file ExifTool but nothing changes.

 

[DazeMae]

Just guessing that you had the box "don't process if DNG exists" checked. If so, it didn't create a new file (with the copied jpg file data) when you reran DNG4PS.

 

[Graystar]

If you're getting an error when you check the box, then you need to check the file name (exiftool.exe) and location (DNG for Powershot 1.1\bin\)

If you're able to check the "Add metadata from jpeg" option without getting an error, then you're all set. The data will be added when you convert to DNG. You won't see any indication on the screen that this is happening.

 

[castaneda363]

Now DNG works better, I solved the problem.

 

[castaneda363]

When I edit DNG file in photoshop it seems noisier than RAW file if i open this in RawTherapy.
It's possible the conversion RAW to DNG make noise?
It's possible that DNG is Noisier than RAW?
What do you think?

 

[Graystar]

Well, I know that when I open a DNG in Photoshop Elements the file comes up in a dialog with several options that are preset, including noise reduction, and the image looks better than in Raw Therapee. I always use Raw Therapee to make my “before” crops because I can select the Neutral profile and see the RAW as is.

Raw Therapee also has different preset profiles you can apply to the RAW file.

 

[DazeMae]

Was that check box the cause of your problem?

 

[gkl]

After being told that RAW isn’t about resolution detail but about
dynamic range, I decided to test it.

The first image is a flash shot of the scene to show the colors and
everything in it. Spot meter readings put the dynamic range of the
scene at just over 8 stops. My A710 only has 6-7 stops of dr, so
this scene was clearly beyond the ability of the camera, and it
sure did show in the histogram.

....

The fifth image is the processed RAW. I was able to recover much
detail and color, and was able to create an image that was close to
what the eye sees.

I must say, I find the results fairly striking. And I’m sure that
with more practice I could make the image even better.

Very interesting test. It shows that RAW can be used to improve images with marginally blown highlights or blocked shadows on a sensor that many have said wouldn't benefit from RAW. It looks like color, contrast and detail in the shadows of the original jpeg were obscured by a combination of noise reduction and JPEG processing.

It's a strong counterexample to Canon's stated reasons for dropping RAW on the G7 (which has about the same pixel pitch as the A710). I'm referring to Mr. Westfall's statements quoted in the following post:
http://forums.dpreview.com/forums/read.asp?forum=1010&message=22488457
cheers, gkl

 

[Graystar]

It's a strong counterexample to Canon's stated reasons for dropping
RAW on the G7

Well, I would say that Canon is half right. There's another thread in which I perform tests for image detail, and found that RAW gave no improvement at all in image detail. But there certainly does seem to be quite a bit that can be done with extending the dynamic range of an image and recovering detail.

Here's the thread on image detail:
http://forums.dpreview.com/forums/readflat.asp?forum=1010&thread=23106264