Color space confusion???

[joe_bailey2]

The more I read about this subject, the more confused I get. I understand the

difference between Adobe RGB and sRGB, but am unsure of what needs to be set. My

monitor is calibrated with the Spyder2. My Canon 5D is set in RGB mode. I shoot

everything in RAW and from what I have read, this does not matter which mode the

camera is in. I use DPP for my RAW conversion. I want to work in Adobe RGB.

Should this color space in DPP be set to Adobe RGB? Should my Adobe PS working

spaces be set to RGB? As expected, I see a difference in color when I assign an

sRGB image to Adobe RGB. I use WHCC for my printing and they prefer sRGB

images. Do I make all of my image modifications in Adobe RGB then convert to

sRGB? Does converting as opposed to assigning retain most of the colors? Sorry

for the long post. Thanks.

[blumesan]

Last time I heard from WHCC they specified that files must be saved with a valid ICC profile embedded and they suggested either sRGB or Adobe RGB (1998). So you could do your RAW conversion; save with the Adobe RGB profile, use the same color space as the working space in PhotoShop and, after editing, save a copy as jpeg (ensuring that profile is embedded) with correct resolution and dimensions, and send it off.

 

Cheers/Mike

[benbangerter]

Joe, what Mike said. The AdobeRGB/sRGB setting on the camera only affects the JPGs created in-camera. You should only ASSIGN a profile to an untagged image (no embedded profile) if you in fact know the color space, or if you don't know, and want to see how various assumptions appear on your monitor. You could simplify your workflow somewhat by working in sRGB all the way if you will always print in that space, but I suggest you work in AdobeRGB if you ever expect to print yourself with a good inkjet printer.

[joe_bailey2]

Thanks for the responses. I have been working in sRGB, but the colors never seemed to pop out. In Adobe RGB, the reds seem to be a little over saturated, but the colors are more vibrant. I do have a Canon i9900 printer which has worked great so far. I haven't tried printing in Adobe RGB yet. I think this color space stuff is starting to sink in. Please correct me if I am wrong:

 

PS working color space is my defalut space when no other profile is embedded.

 

If the image is in sRGB, assigning the Adobe RGB will show me the color gamut in that mode.

 

Converting to another color profile will try to retain the colors of the assigned profile.

[blumesan]

Joe, In response to your questions (assumptions):

 

 

Yes, the PS working color space is the default color space when no profile is embedded in the image. However under the normal workflow you have described, you should not encounter this situation. PS will warn you (if properly configured) when the image has no embedded profile. In that case you should assign the correct profile, if you know what that is.

 

 

NO, If the image is in sRGB you should not ever assign Adobe RGB. This will give you an incorrect rendition of the colors. If necessary you may convert sRGB to Adobe RGB in order to edit in the larger color space. Again, given the described workflow, this situation need not arise.

 

 

Converting to another color profile will try to retain the colors of the original profile to the extent possible. You might wish to read a bit about "rendering intent" in this regard.

[benbangerter]

Joe, each of your three statements is incorrect:

 

"PS working color space is my defalut space when no other profile is embedded." You can choose to work in any standard color working space in Photoshop (sRGB, Adobe RGB, etc). You could also choose to work in a device-dependent color space (as for a printer or monitor) which would be an exceedingly bad idea. Behavior depends on your Photoshop preferences [Menu>Edit>Color settings... Color Management Policies box, select "Preserve Embedded Profiles" for all three entries, check all three boxes is what I recommend]. When you open a file tagged with your working space, the file opens in that color space. When you open a file tagged with a different space, or with no embedded profile, Photoshop asks what you want to do. If there is no embedded profile, you may choose to assign the working profile (or space - same thing), assign some other profile, or simply abandon color management. If there is a profile mismatch, you may choose to use the embedded profile, convert to the working profile or abandon color management. It is always best to work in some standard space, most likely sRGB or AdobeRGB.

 

"If the image is in sRGB, assigning the Adobe RGB will show me the color gamut in that mode." No, assigning a profile to an image that has a different profile will change the appearance of the colors (on screen or in print) while leaving the pixel RGB values unchanged. There is no good reason to do this, other than to amuse yourself. Since sRGB has a smaller gamut that other commonly used color spaces, assigning AdobeRGB, or WideGamut, or ProPhoto or EktaSpace will generally result in much more saturated colors. Try it. The only way to compare gamuts is to look at gamut plots. You will find these in books or articles on color management. If you use WinXP, the availambe Control Panel Color applet will also work for this.

 

"Converting to another color profile will try to retain the colors of the assigned profile." Converting to another profile will preserve the appearance of the colors as much as possible, whils changing the pixel RGB values. Note that when converting from a larger to a smaller gamut, any color values outside the smaller gamut will change in appearance, perhaps only slightly.

 

Whew! You are right, this is a complicated and confusing business. But it all does begin to make sense eventually. There is a lot of information on the web, as you are no doubt discovering, and a good book (such as Fraser's "Real World Color Management") is very helpful.

 

Stick with it, and have fun!

[joe_bailey2]

Thanks for the great explanation. I went ahead and ordered the book. It's starting to make a little more sense. I was confused when I assigned an RGB profile to an sRGB image. The colors looked more vibrant, which I liked. This probably could have been properly achieved by adjusting the image color saturation.