Color setting questions in Photoshop

[kat.hayes]

I am confused about the purpose of edit > color settings

If I make a new blank file in Photoshop I setup the colorspace as Adobe RGB right there

If I import a photo taken with a DSLR it imports the embedded color space of the photo

1. What is the purpose of changing this color space under edit > color settings?
2. Under Working Spaces, I have it set to Adobe sRGB, though I am not sure what the CMYK setting is for? Again, what are these for, this is not the place for printing and this should be embedded in the file.
3. What about the Gray and Spot settings? Again, what are these for, this is not the place for printing and this should be embedded in the file.

Thanks!!!

 

[MechaSpanky]

kat,

RGB (which is Red, Green, Blue) is a color spectrum. RGB is used on the web and for video. RGB is not used in commercial printing. Most photographs are taken using the RGB color space because it captures more color but those colors are not always capable of being reproduced so the photos must be converted to CMYK so that they can be printed. RGB has three channels, one for each color.

CMYK (Cyan, Magenta, Yellow, and Black) is a range of reproducible colors. CMYK has a narrower range of color than RGB. Most all photos that you see printed in magazines, newspapers, etc are printed using CMYK or spot colors. CMYK has four channels, one for each color.

Spot color: Spot color is a way to get more vivid or stronger colors without using CMYK. Sometimes spot colors are used so that the color appears cleaner and sometimes they use spot colors to save money (using black plus one spot color saves half the money of regular CMYK). In Photoshop, spot colors have to be on their own channel. Sometimes companies use spot color with CMYK as well.

Greyscale: is for one color printing. It is only one channel so when it is printed, it is only one plate. You can have a CMYK or a RGB photo that looks black and white but it will have 3 or 4 channels. A true greyscale image has only one channel. It is used heavily by newspapers and other publications.

So being able to control and change the color space is very important for printers, designers, photographers, video editors, etc. If you are a photographer and you take a stunning photo but some of the colors are outside of the reproducible color range of CMYK, when it is printed it will appear darker and kind of "muddy" looking. You will be disappointed in the results unless you take the time to adjust the colors first in Photoshop.

 

[spacedcadet]

Colour Settings is slightly different to the typical Image Modes (RGB, CMYK etc), it's an additional control which amongst other things sets out how your document behaves in terms of embedded colour profiles. The screenshot shows a typical setup for print using an international standard ECI profile. With a correctly calibrated screen you can then get a consistent representation for output. You can also change the profile if necessary for a different workflow. It can also be set up via Bridge to be applied consistently across the CS apps (advisable!).