Obviously you could just convert the modes and accept whatever discrepancies that show up, then adjust the cmyk afterwards. Or you could choose select/color range/out of gamut and reduce the saturation/hue of the offending areas. However I have always been a bit confused as to how this works, if you choose view/out of gamut and begin desaturating these areas (with say the sponge tool) you often have to reduce it to a grey mush before the gamut warning begins to fade, not only that changing those areas makes them stand out against their surrounding areas so I clearly haven't got the hang of this yet.

Could someone explain a better way to do this.
Thanks

That's a really subjective question.

What I tend to do is convert to CMYK, then save that as a copy, and open the original & compare them side by side. If photoshop has dulled some colors unnacceptably in the conversion process, you can tweak them in CMYK until they match the RGB file more closely.

I tend to work in CMYK alot, since most of what I do is for print. If you need to make an adjustment that you can't do in CMYK, (some filters only work in RGB)it's no big deal to go back and forth a few times.

You can also tinker withe the color settings. I prefer to set black generation on light, total ink limit 300%. you can still produce a pretty bright, saturated image that way. Of course, it's polite to check with your printer and ask them what their preference is there. (Hint: If they don't know, find another printer.)

If you want to get relly heavy into it, you can track down color look-up tables for their inks (most ink manufacturers should be able to provide them, at least in the offset and silkscreen arenas) and set those up, which may provide you with a wider gamut than whatever photoshop defaults to. My t-shirt printing inks have an appreciably wider gamut than web offset newspaper ink.

There's some good tutorials on the subject out there-- there's a couple websites in particular that have in depth info. I'll try to track down the URL's in a bit.

CV

Thanks a lot Chris, I'd never thought to compare them side by side as such. As regards the ink prefs - I've never touched it. There has always been a large element of chance in my print output, however I'm now working on A0 size prints which are going to cost in the region of £100.00 each to produce, so obviously I need to learn more.

Should you come across any useful url's, do post them here. I'll do likewise.

Here's a couple-- I've got a better more color mgmt.-specific tutorial bookmarked at home. I'll post it later.

I think these folks are mainly trying to sell books and seminars by posting teasers on their websites, still some of it might be useful
http://www.planetphotoshop.com/tutorials.html
http://www.digitalmastery.com/ultimateguide/index.html

CV

Here's a curious site which I only discovered recently, sounds a bit too good to be true, I haven't tried them out yet but.. http://www.allexperts.com/getExpert.asp?Category=1028

Obviously http://www.allexperts.com/ will give you the index, for all other subjects.

This is the the best tutorial on color management I've seen. The guy's website goes on for days. This one tutorial is ten pages long, and he's got several more on other subjects.
http://www.ian.lyons.btinternet.co.u...op_6/ps6_1.htm

CV

Wow! that's really comprehensive, thanks.

Download the PS5.0 Monitor set-up file at ftp://ftp.artistat.com/Downloadable/.

Unstuff it and in Photoshop->File->Preferences->ColorSettings->RGB choose custom and load the BruceParams file as your colour set-up.

The long and the short of it is:
1) a CMYK print can't possibly represent accurately your RGB screen.
2) your RGB screen can't possible represent accurately your CMYK result.
3) Adobe's choice of the sRGB colour space is OK for video production but very limited for print production.

The Bruce param file was developed by serious people dealing in the professional pre-print business and will give you much better results than the default Adobe params. I have produced many scans, large scale posters and colour separations and never had a client with a reasonable complaint using these params.

Everyone - please avoid the temptation to "tweak" your CMYK file on screen. You can't possibly know what you're doing because there are a lot of factors involved, including the fact that your RGB monitor can't properly preview CMYK. Instead, invest in a decent colour proof and then ask yourself -- is this a reasonable representation of what I expected to get?