Don't even want to call this one "colour management"

smiley guy · #1 12-22-2005, 06:52 AM

I'm pretty sure there is a quick answer to this one. I have searched the archives etc. and found some convoluted answers but just wanted to double check what I am doing...

Me: iMac G5 with Photoshop CS2, working in AdobeRGB
Them: photolab with Fuji Frontier 375 in sRGB

When I do my normal r&r work I should(?) be working in AdobeRGB but when I am working on a document/photo to output to the photolab I should be working on that photo with the sRGB color profile? It seems to me that if I work on it in AdobeRGB and make all the adjustments and then convert to sRGB it looks radically different. Please correct me if I'm wrong.

Just looking for some clarity. The photolab is good/convenient/fast etc. but would like for my output to more closely match their output.

briarrose · #2 12-22-2005, 10:25 AM

You'll probably get lots of contradictory answers to this one...but I would say you are correct--if you're going to output to sRGB--you want to edit in sRGB... That's how I work, anyway! :-)

(And if your lab offers printer profiles to download--then download and install them--and use the soft proofing feature in Photoshop while you're editing. My lab doesn't--but they print using sRGB and that's what I edit in--and I get very accurate prints back.)

smiley guy · #3 12-22-2005, 10:57 AM

So, assuming that I have my monitor calibrated correctly and they have their machine calibrated correctly, if we are both working in sRGB it should match, right?

Doug Nelson · #4 12-22-2005, 01:54 PM

It won't match exactly, it can't match exactly. No exact match is possible. But it should be close enough to be acceptable (the best we can ever hope for).

And sRGB is a smaller space than AdobeRGB, so I'd recommend working in sRGB from the beginning.

If you're noticing color shifts when changing profiles, verify that you're converting, not assigning (but not changing at all is best).

briarrose · #5 12-22-2005, 02:08 PM

Doug is right...on all counts. :-) You won't get an exact match--but it can be pretty close.

Again--working with printer profiles and soft proofing can help achieve even more accurate results...because different printers (and papers!) render colors slightly differently. (Ie, my prints from mpix.com tend to be slightly cooler...whereas when I used to use ezprints.com, the prints were warmer, almost orange. Smugmug.com uses ezprints to print--and also has several easy to follow pages of information about printing, and color spaces in general: http://www.smugmug.com/help/display-color (explains how to enable soft proofing, using a printer profile) (Also, check out the menu, on the far left, to read more on "getting great prints" - it's geared towards their site--but is useful general info, as well.)

goose443 · #6 12-22-2005, 02:19 PM

One of the reasons people recommend working in AdobeRGB and then converting to your printer profile (and making the necessary changes so it look good again) is that since AdobeRGB is a larger gamut you'll have more information to play with if you ever have to output to a different device. If you're sure you'll only ever have to output to an SRGB device I would work in SRGB but if you feel you might take your work elsewhere or to different media such as broadcast or web, it is recommended that you work in the larger profile and the create a duplicate file that is adjusted using the SRGB profile.

I completely agree with Doug and Briarrose in that you will never get a completely acurate result but generally the differences aren't that drastic.

briarrose · #7 12-22-2005, 02:58 PM

Goose443 makes good point about keeping your options open for the possibility of outputting to different sources...I would only like to add that for web, at least, sRGB is still the way to go. Or at least it is for Windows users--since Windows uses sRGB as its default display color space. (I believe that Macs use a different default...and probably Linux does, as well...*sigh...*)

I once switched my default color space in Photoshop to Adobe RGB 1998 for a few days, edited some photos, and then switched back...and when posting images to the web, had a couple of stubborn pix that looked COMPLETELY different on the Net...and I couldn't for the life of me figure out why they looked fine in Photoshop, and lousy online! Felt pretty stupid when I checked out the embedded profile...and realized that Windows was simply ignoring it. Doh! ;-)

Oh wait...wasn't this sort of esoteric discussion exactly the sort of thing you were trying to avoid? Ah--but color management is so darn fascinating! :-)

Swampy · #8 12-23-2005, 06:57 AM

Since 99% of my work is high resolution process color pre press, I use Adobe RGB and always save a copy in that format. The final step of my work flow is to convert to CMYK and save as a TIFF file.

I have two color houses that do my print jobs and both have provided me their ICC profiles. I select the ICC for the printer that will do the print job before I convert to CMYK so that my TIFF file matches their profile. Results have been very consistent using this method.

Another tip. Set your Preferences for gamut color to something extreme for the graphic you are working on (I use lime green a lot) and under PhotoShop's View options, set to "View Gamut Warning". From time to time, toggle this option on/off and you can easily see the areas of color that are outside the CMYK print range and that will shift when converting from RGB to CMYK. This allows you to make your own adjustments (desaturations, etc) before converting. Also, under Select Color Range, there is an option to select everything that is out of gamut. Very handy!

briarrose · #9 12-23-2005, 12:26 PM

Swampy--I'm curious as to whether or not you go from Adobe RGB directly to CMYK--or if you convert to LAB, between the two... I was discussing this with someone recently, and he swears that you get less color shift if you switch to LAB first. A quick trial on a document or two of my own seemed to confirm that--but was wondering if others found the same thing to be true...

Swampy · #10 12-23-2005, 08:11 PM

Briarrose..

Never have gone to Lab color before converting to CMYK. Never really saw a need to. If the graphic has a lot of "hot" colors in it, I usually do the "view gamut thing". If the amount of out of gamut color is significant I'll do the Select Color Range-out of gamut and then use a Hue/Sat adjustment layer to lower the saturation on those areas until the out of gamut area is minimal. (I don't mind if I leave a few hot spots and I let the Convert to CMYK process convert those areas for me.) I do want to be able to control major hot spot areas myself though.

briarrose · #11 12-24-2005, 08:57 AM

That makes sense, Swampy--thanks for your explanation! :-) I'm familiar with the gamut warning feature, but haven't used it much. I hadn't really thought of using it as a tool to use in conjunction with moving between color spaces--I think I'll have to play with that now! :-)

Swampy · #12 12-24-2005, 10:53 AM

The "View Gamut Warning" and especially Select-Color Range-Out of Gamut are pretty powerful, but simple tools. The key is to key in on the areas in the main subject of the photo and control the Hue and Saturation of those zones. I don't worry too much if small areas of background aren't within gamut or shift during the conversion. I usually just tweak H/S so that the focal point of the photo is "cooled" down.

I'll have to experiment with going to Lab Color before converting to CMYK. It's a scarry thought to just let Photoshop control the color space. I'm so used to wanting to control it myself.

briarrose · #13 12-24-2005, 01:46 PM

Quote:

It's a scary thought to just let Photoshop control the color space.

LOL!!! Aren't all retouchers and digital artists control freaks, at heart? ;-) I feel the same way...hate to let anyone or anything else make my decisions for me...

And thanks for the tip on using Hue/Saturation to "cool down" areas of an image that're out of gamut... I'll give it a try! :-) I generally work in sRGB or LAB (for editing), only sometimes needing to wander into CMYK territory...but I think it's always good to stretch yourself and try new things, so suggestions like yours are terrific. (And I have recently been doing more editing in CMYK, just for the sake of practice--so this is a timely suggestion, as well! :-))

smiley guy · #14 12-29-2005, 02:01 PM

Great help everybody! Thanks for the fabulous responses. I haven't had any output lately to test the input/output process for my computer to the lab etc. but I'll be working on stuff this weekend and see how everything turns out.

It's not an "easy" issue this colour management...

smiley guy · #15 01-03-2006, 11:44 AM

Ok, I had some stuff printed over the weekend and was working in sRGB with sRGB as the embedded profile. Everything printed out really nicely from the lab with the fuji machine. Very happy to say the least. Once I brought them home they compared quite favourably to the same pics on my display. Needless to say I am thrilled about this as it seems I can now trust to some extent my work on screen and the work from the lab.

Thanks for all your help on this one.