sRGB CMYK RGB

[jchooper12]

Aghhhhh.

Ok, my question is...
I understand for Web you should save you photo with the sRGB profile. For print it should be CMYK. Ok, first of all why?

Second and my bigger problem.
When I convert a photo to CMYK the look of the image changes drastically and I cannot get it to look like it is supposed to. What are the techniques for editing the photo to get it back to what it looks like in RGB?

[bbailey]

I've never converted to CMYK for printing photos. I think that is used mainly for larger presses, etc. Usually its recommened to print in Adobe RGB (aRGB), and post on the web, view onscreen in RGB. Of course, if you shot in RGB then converting to the larger aRGB color space won't have any benifit.

I'm sure someone here can explain the details better than me.

[jtford]

Originally Posted by jchooper12

Aghhhhh.

Ok, my question is...
I understand for Web you should save you photo with the sRGB profile. For print it should be CMYK. Ok, first of all why?

sRGB is what basically every analog monitor ever made is set to. (Not really, but it's as close as you're going to get.)

CMYK is how process offset printing is done. Paper is run through four ink units, each one transfering part of the image to the paper.

Conversion is neccesary. Skipping the tech details, if you send your images for offset print in any form of RGB, you'll get one of two things (assuming someone doesn't call you back, force you to change the color mode and re-submit your files).

1) All of the image will be piled onto the Black (K) plate, and the final piece will be a funky black and white...or:

2) It will be converted for you, either by one of the prepress operators, or automatically by the RIP (the device that processes your images for printing). There is a chance you'll be happy with the results. That chance is very small.

Second and my bigger problem.
When I convert a photo to CMYK the look of the image changes drastically and I cannot get it to look like it is supposed to. What are the techniques for editing the photo to get it back to what it looks like in RGB?

Short answer: you can't.

Longer Answer: you can, with practice, learn to minimize the differences to a great degree.

Even Longer Answer: This is where the concept of Gamut comes in. Gamut is the range of colors out any given output device can actually produce. A monitor, which is backlit, produces a different range of possible colors than ink laid on paper.

Worse, even though there are more color components in CMYK, that ink on a sheet in reality produces fewer colors than sRGB, and fewer still than Adobe RGB, and lots fewer than 16-bit RGB of any sort. There are large ranges that don't overlap at all - vibrant blues, for example, that are a royal pain for even very experienced color correctors to compensate for.

And before this gets any longer, I need to add that for color inkjets - and this includes photographic process print, like Frontier - you use RGB, preferably 16-bit Adobe RGB. These machines usually have the Gamut to handle the full range and are usually expecting RGB.