ACR v. Capture NX

dusty-dog · March 9, 2008

I'm sure there have been tons of threads that have discussed the benefits of one over the other. But, I just noticed something this morning. As I was processing images of my cat that I shot last night, I decided first to just go the quick and dirty, by using only ACR, then finishing in CS3. The outcome seemed quite good, and I really liked the image. But then, I decided to go the slower route, using NX first, then finishing in CS3, as I usually do. The differences were stark.

First, the color in ACR wasn't as accurate. That may be a function of not being quite as familiar with using ACR as I am with NX. But, the most surprising finding was the resulting file sizes. The finished .jpg converted in ACR is 4.72 MB. The finished .jpg converted with NX is 7.54 MB. Both are full frame, no cropping at all, and both are 300 dpi, 8 bit (obviously) jpg's.

For comparison, here are both images, and I love some feedback on the postprocessing and the issue of file sizes. Thanks.

The first is the one converted in ACR.

The one below was converted with NX.

Duffy Pratt · March 9, 2008

My only thought on the file sizes is that maybe different compression levels were being used. In PS, you can choose compression levels from 1-12. I don't no about CaptureNX, but I do know that some other programs have different compression levels that they allow, which basically put different gradations along the same scale.

To my eye, the color is off in both of them, but worse in the ACR conversion. Cats don't have blue fur. You could do a couple of things in ACR -- Either white balance for the bluest part of the fur, which will warm everything up. Alternatively, you could get the color balance the way you want elsewhere in the shot, while ignoring the fur. Then go to the HSL tab and desaturate the blue, and perhaps the aqua. When I do this, I think it also helps to darken the areas that I desaturate in the fur.

Here's your ACR version, re-opened in ACR. Then the I simply de-saturated the blues and darkened them some with the HSL sliders. The result should be better if this were done in RAW.

Duffy

dusty-dog · March 9, 2008

It always amazes me how fast we get answers here.

Anyway, thanks so much for your input and your effort. Yeah, cats aren't blue. I will definitely pay more attention to the warming tools. I generally shoot with auto WB. But then, I tend to forget about warming the usually too cool image. Something I'll be paying more attention to from now on. I promise.

As for file size, the image processed in NX was saved first as a nef, then "save as" a 16 bit, uncompressed tif. Then opened in CS3. The ACR coverted was also saved as a 16 bit, uncompressed tif. Both were then saved as maximum 12 jpg compressions. Amazes me how different the resulting sizes are. Does the NX tif save also save more data? I just don't know.

arodney · March 9, 2008

dusty-dog wrote:

First, the color in ACR wasn't as accurate. That may be a function of not being quite as familiar with using ACR as I am with NX.

Yes in that the color isn't accurate or inaccurate until you render the image as you wish. The default rendering of any Raw converter is correct much like whatever default filter pack you had in your color enlarger will be right for the next print you make.

You may want to read these two articles on the subject:
http://www.color.org/ICC_white_paper_20_Digital_photography_color_management_basics.pdf
http://tinyurl.com/33msxz

dusty-dog · March 9, 2008

Below is my lastest rendition, warming the image to remove the blue cast. It's kind of a tough call to remove the blue, but keep the whiteness, and thereby not making it too yellow. Quite the balancing act, me thinks. I guess that's why they call it "white balance".

Thanks so much, Andrew, for those links. I'll definitely check them out.

pathfinder · March 9, 2008

Diane,

What lighting was used for this image of your cat?

Duffy's edit certainly gives a gray - neutral - no blue, no yellow cat. But, I wonder what color the light actually was. Was this shot by window light perhaps? Not electronic flash, and probably not sunlight either.

In shade, a white cat might look just a bit of the blue, maybe?

dusty-dog · March 9, 2008

pathfinder wrote:

Diane,

What lighting was used for this image of your cat?

Duffy's edit certainly gives a gray - neutral - no blue, no yellow cat. But, I wonder what color the light actually was. Was this shot by window light perhaps? Not electronic flash, and probably not sunlight either.

In shade, a white cat might look just a bit of the blue, maybe?

Actually, I used an SB-600 flash on a Nikon D200. No window light. It was night time, anyway. Minimal light, which was flourescent (energy saving thing), and was behind me. She was sitting in my hallway, where there was nothing near enough behind the her to be illuminated by the flash. I was lying on the floor in front of her (obviously). Behind her is my bedroom, and the light was out. I have no idea what caused her to look up, as there is nothing there but a white wall. Whatever. It worked for me.

Camera settings:
1/60 sec.
f/7.1
55mm
ISO200
SB-600 flash exposure comp. -1.3 EV

The image was a bit underexposed, but nothing that couldn't be adjusted in Capture NX or ACR.

Duffy Pratt · March 9, 2008

Under this kind of lighting, I probably would stick almost to a pure neutral, or I might warm it up a little. Indoor lighting tends toward the warm (discounting the ugly green flourescent which its usually better to ignore). A person on the scene, looking at the cat, would most likely see the chest as white, or at least interpret it as white even if it was possible to make it out as something else. There is nothing in the shot to show the source of the light.

When I do this with my own dogs, who are pure white when clean, I usually don't desaturate all the way. I'll take it down to a point where there are some very subtle color variations going on. Of course, all of this eventually comes down to a matter of taste.

Duffy

BinaryFx · March 10, 2008

dusty-dog wrote:

It always amazes me how fast we get answers here.
As for file size, the image processed in NX was saved first as a nef, then "save as" a 16 bit, uncompressed tif. Then opened in CS3. The ACR coverted was also saved as a 16 bit, uncompressed tif. Both were then saved as maximum 12 jpg compressions. Amazes me how different the resulting sizes are. Does the NX tif save also save more data? I just don't know.

We would need to see crops of the original pixels, my guess is that the NX processed raw to TIFF has less noise reduction, more detail and or "micro-detail" and perhaps more sharpnening than the Adobe render from raw to TIFF. I can't speak for NX, but I know that the basic processing results of some other converters offer results that I prefer to ACR/ALR for detail (I still prefer the speed and workflow of ACR though).

Another issue that adds to file size is the "dither" option in the colour settings preference and convert to profile in Photoshop, although I don't think it is coming into play here. Detail, sharpness and noise (chroma or luminance) all affect JPEG compression, thus two different renders from different converters may indeed result in very different file sizes.

As for the colour, are you saying that with NX and ACR using the "same" WB settings (as shot?), you prefer the NX over the ACR colour? This is of course just a starting point and one can render whatever WB they wish. This may indicate that ACR may benefit from custom calibration so that it performs at a better default than it currently does for your particular camera when using preset WB settings and not manually setting the WB.

The camera maker's software also has the benefit of knowing the secrets of their own camera and raw format so they can sometimes offer better colour or exposure moves or whatever, but may fall down on the interface or workflow when compared to ACR/ALR or other packages.

Regards,

Stephen Marsh
http://members.ozemail.com.au/~binaryfx/

ACR v. Capture NX

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