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When I edit a RAW file in Photoshop or Nikon's ViewNX 2 software, there's a wide range of things I can adjust. For example, when I open a RAW file in Photoshop, I see the following options:

Screencapture

  • White Balance
  • Temperature
  • Tint
  • Exposure
  • Recovery
  • Fill Light
  • Blacks
  • Contrast
  • Clarity
  • Vibrance
  • Saturation

Which of these adjustments are specific to the RAW file? Should I ignore any of these adjustments when importing RAW files into Photoshop? For example, I can adjust Levels, Brightness and Saturation after I have imported a RAW file into Photoshop (or on any Photoshop document, even a JPEG). Is Image > Adjustment > Hue/Saturation different from the Saturation adjustment when opening a RAW file in Photoshop?

What adjustments are specific to RAW files?

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Expert comment on this assertion is welcome: "Real" white balance is specific to RAW. But you can adjust the effects if white balance subsequently. –  Russell McMahon Apr 3 '12 at 3:14

3 Answers 3

The only one "specific" to RAW files should be the temperature slider. However using a RAW file will make all of the other ones much more effective, especially the exposure tools.

The reason for this is that a RAW file maintains the full data for the image, which is usual 12-14 bits of information per pixel. When you render down to jpeg, or even 8bit tiff, it throws most of that information away and you are left with 8 bits of information per pixel.

To give you an example, lets pretend we're dealing with a black and white image (grayscale). In an 8 bit image, each pixel can be one of 256 shades of gray (plus absolute black and white). That's enough to give you a smooth gradation if you don't need to mess with the image much. However, once you start changing exposure or contrast after the fact you will start introducing gaps where you don't have enough shades of gray to work with. This is when your image starts to have a blotchy or posterized look too it.

12 or 14 bits gives you around 4,000 to 6,000 shades to work with, which is waaay more data to push and pull around before the image starts to break up and look bad. It gives you a subtle details like clouds that would normally be blown out to white or shadows that would be crushed to black in an 8-bit jpgeg.

When working with color, the only difference is you have shades of Red, Green, and Blue instead of gray.

To summarize, you only get one additional slider, but a lot more power using RAW.

EDIT:

I should also say that the temperature slider is actually very important and powerful by itself. You can't get very far with tint alone in terms of correcting a color cast or changing the overall tone of a picture.

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That makes a lot of sense, thanks! (I'm a programmer so I am very familiar with how just one bit more gives you vastly more information) –  Josh Apr 2 '12 at 21:38
    
I'm a programmer too, glad I could help. –  cadmium Apr 2 '12 at 21:41
2  
Are you aware that TIFF, JPEG200, PNG, etc., can store 16 bits per channel (and OpenEXR 32 bits per channel)? –  Jerry Coffin Apr 3 '12 at 4:54

Only white balance is specific to RAW, but all of those (exposure, blacks, recover, fill, etc) are non-destructive adjustments to the RAW file, so they can be done equally in either program.

If you edit a RAW file with View NX2, then subsequently open the RAW file in Photoshop, Photoshop will not take notice of the adjustments made by View NX2. If you open as a TIF then the adjustments will be factored in, but you will no longer have a raw file, so you've lost the non-destructive benefit and you're no longer working with a RAW file in Adobe Camera Raw.

So it's really pointless to make edits in View NX2, if you intend to make further adjustmens to those same sliders in Photoshop. It just doesn't work. To repeat: either you lose the View NX2 adjustments if you continue to work with the RAW file, or you have to convert to TIF and are no longer working with a RAW file in Photoshop.

The only reason to use View NX2 or Capture NX2 is if you feel (as many do) that they do a better job with the Nikon RAW file. That is, they initially show a better representation of how Nikon believes the image should look, including things like Picture Controls, which ACR does not factor in. But once you start moving sliders, I don't think there is anything View NX2 does better than Adobe Camera Raw.

In my opinion, you're better off opening the RAW file in Photoshop/ACR and doing all your edits there. If you open into Photoshop as a Smart Object from ACR, then you can even go back and make non-destructive changes to the RAW file.

And yes, there is a big difference between adjusting saturation in the RAW editor and doing via an image adjustment, and that is that RAW edits are non-destructive (you can easily reverse or change them), and you can make many RAW changes without degrading the file. This is not true of adjustments made via the Image menu.

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Thanks; I am not opening NEF files in View NX 2, adjusting, and then opening those same files in Photoshop. I have been experimenting with different programs to find the workflow I prefer. I was curious (in this question) if basically I could ignore any of the sliders in the RAW adjustment dialog because those same adjustments are available after importing. –  Josh Apr 3 '12 at 11:42

Some of this depends on the program. A few (e.g., RawTherapee) let you select things like the demosaicing algorithm:

enter image description here

This is definitely specific to raw files, as it controls the method used to convert the raw data into pixels.

Likewise in the Detail pane of Adobe Camera Raw, you have some adjustments that aren't really duplicated elsewhere, at least in Photoshop:

enter image description here

These, again, are really controlling how the raw data is converted into pixels, so while there are somewhat similar controls in other parts of Photoshop that have (in some cases) identical names, they seem to actually work at least a little differently.

Some other controls might at least theoretically be possible after conversion, but are (at the very least) a lot more commonly available before or during raw conversion than afterwards. The most obvious would be adjustment for chromatic aberration. In Adobe Camera Raw, you need to change from the Basic adjustments to the Lens Correction pane to see these controls:

enter image description here

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+1 for the demosaicing algorithm. After you have demosaicized (!) it's too late to go back. –  Francesco Apr 3 '12 at 5:33
    
Thanks, this is very helpful. I'll check out Adobe Camera Raw! –  Josh Apr 3 '12 at 11:38

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