It was 24/11/02 1:32 pm when Geoff Dor� wrote: > - is this the general consensus? I seem to be getting different advice > from different experts..... even the 'Bible' (Photoshop 6 - Martin > Evening) only mentions it once but doesn't say whether it should be > ticked or not ticked.....
Geoff - It has to be ticked. That much I do know about color management! Here's what Stephen Marsh had to say on the Photoshop Discussion Group about color management in Photoshop 5. I hope he won't mind me quoting a large chunk from it. I recommend you have the lie down *before* you start reading it. You sure will need one when you've finished! <G> "This will be a huge post, but this is a huge topic - with luck it will help others in your situation. >Snip Firstly, here are the links which I taught myself CM with. These were gained through months on searching: http://www.adobe.com/support/techguides/color/photoshop/main.html http://www.adobe.com/support/techguides/photoshop/cms2/cmwork.html http://www.adobe.com/support/techguides/color http://www.adobe.com/support/techguides/color/colortheory/main.html http://www.adobe.com/support/techguides/color/gamma/step04.html http://www.btinternet.com/~ian.lyons http://www.digitaldog.net/tips.html http://www.thelawlers.com/essays.html http://www.thelawlers.com/ClearingHouse.html http://www.color.org/wpaper1.html http://www.imagequality.com/dtp/colmgt.html http://www.adobe.com/support/techdocs/f71a.htm http://www.xrite.com/documents/mktg/L10-001.pdf Now every user is different and has different needs. Below is the method I personally use - which works well for me. Your case might be different - but with luck my 'dumbed down' explanation will make more sense once you start reading the complex links listed above. This is not an easy subject, but it does make sense after some time and practice. I helped another forum user at photoshopcentral.com with setting up colour management, for a specific workflow (which works well for many users in a professional imaging setting which work with many other users). Here are the step by step instructions and some theory on why each is chosen: "...I can now see that you are an imaging professional dealing with other professionals (as well as the type of work you do and equipment you use). Your images will probably be used by many different trades - from print to multi media. Flexible colour management will be a huge benefit to you. First off forget everything you might know about colour handling in APS4 or earlier...things have changed big time! It helps if you understand legacy (APS4) colour handling, but this is not really that critical for day to day use. This whole post presumes that you do want to embrace ICC profile based colour management. Photoshop 5 colour handling can also be made to behave just like version 4 - dumb but easy to use! In your professional setting, where you interact with others I would try to make the advanced colour handling features of APS5.x work. Things can be roughly covered in 5 basic sections: Monitor calibration/characterisation, APS RGB setup, APS CMYK setup, APS Greyscale setup & APS Profile Handling (which sparked your initial question!). Here are my recommendations on how I would go about setting up Photoshop 5.x for your work flow: 1. Monitor Calibration & Characterisation: First use Adobe Gamma to calibrate and characterise (profile) your monitor. Special hardware/software calibration and profiling is best, but Adobe Gamma is the only choice for most of us with limited budgets. A good ICC profile is needed to start with Adobe Gamma...If you don't have a generic .icm file for your Lacie 21", then you can make a profile using APS5.x by entering the specs stated in the monitor manual for gamma, phosphors, white point setting etc. After you go through the step by step "wizard", Adobe Gamma will prompt you to save your new ICC profile into the colour profile folder on your hard-drive (give this .ICM file a descriptive name). In a Win98 OS, this ICM file would live in C:\WINDOWS\SYSTEM\COLOR or something like that. Next go to your Start button\settings\control panel\display On one of the tabs there will be an "advanced" button or some such name...under here is a sub-tabbed menu where you will find a colour management option. Load/Select the .ICM file you just made in Adobe Gamma to tell your MS OS that you are using a custom monitor profile...instead of the default sRGB monitor colour space. Also check out the C:\WINDOWS\SYSTEM\STARTUP...or just WINDOWS\STARTUP... There should be a shortcut file to your Adobe Gamma Loader.exe file here. This is very important, if this is missing or broken, Adobe Gamma will not launch when your system does...NO MONITOR CALIBRATION! When you restart your OS, you should see your monitor slightly change brighter/darker as the loader .exe file kicks in. Now that your monitor and operating system have been taken into account, it's time for Photoshop (all these settings are found under the file/colour settings menu in APS...). _____ RGB Setup: >From the first RGB drop down menu, select a preset editing/working colour space... This was not much of an issue before APS5, but RGB working spaces are a very deep issue...too deep to go into here... I would choose COLORMATCH RGB if I was mainly into print. ADOBE RGB in 5.5 (SMPTE-240M in APS5) would be a good choice for all round work, especially if your images go to wider colour gamut devices than traditional printing. Once you have chosen a preset colour space...DO NOT CHANGE ANY OTHER SETTING in this section of the dialog box! I don't know why Adobe let you edit them anyway...if this is needed there should have been a custom option...it is important to keep these industry standard colour spaces to specification (that's the whole idea behind standards, they can't be changed!). In the "Monitor" section of the RGB setup, you will find the ICM profile listed that you set using Adobe Gamma. Make sure that "Display using Monitor Compensation" is active...this must be checked/ticked! Your monitor is a known entity (via the custom profile you made)...your industry standard RGB working space is also known...Photoshop now takes your monitor into account when displaying the working space colour! This may not sound like much, but it is a HUGE step forward over Photoshop 4 and other non ICC image editors. _____ CMYK Setup: This section is best changed each time to a specific setting/s which matches the press you will use. Since you use desktop printers (which are fed RGB data), you probably don't have to convert many pics to four colour process...I will leave this section alone 'til some other time. You are safe to leave the default "built in" colour engine and SWOP Coated 20% settings which default upon installation. _____ Greyscale setup: This should be set to "black ink" to display expected dot gain for print...but if you are working in RGB, set it to RGB (or choose RGB if you are not sure, this is how APS 4 sort of worked). _____ Profile Setup: This is perhaps the key to colour management in Photoshop. Like RGB working spaces, you can write a whole book on the pros and cons of this area of colour handling alone! I will only briefly explain why each choice is made. This is all personal preference, but there are good reasons for the settings I recommend. * Embed Profiles: Photoshop can embed an ICC profile into your documents. The specific colour settings for RGB, CMYK and Greyscale are "tagged" to your image file. Other ICC aware applications and hardware can then read the profile...then the input colour is mapped to the output colour...this is colour management in action! Usually all files should be tagged with a profile...exceptions are greyscale images for some people (for example, Adobe PageMaker has an annoying bug which can be avoided by removing profile embedding only for greyscale images). Internet pics are also usually tag free, as file size is more important than colour accuracy. If you intentionally deselect profile embedding, Photoshop writes a specific bit of code so that it will not try to colour manage this file (as you told it not to!)...this is a great little feature. * Assumed Profiles: This section deals with images which do not have a colour profile tagged to them. If you convert, the colour values will change - but the image will look correct. If you don't convert, the files pixel colour values will not change, but you will probably not see accurate colour...thus all visual edits will be based on invalid decisions. You are safest deciding things on a case by case basis for Assumed Profiles. Often you don't care about the original images exact pixel values...you just want the image to look as intended by the author (convert). Other times, like doing web interface work - you don't care how it looks...but it must retain it's exact mix of colour values, otherwise it won't match the other elements (don't convert). For RGB I recommend you choose "Ask When Opening". For CMYK and Greyscale I would use "none". No colour conversions will take place for these images. Exact colour values will be retained, but things may not match your current colour settings and view incorrectly. For me this is the better of two evils (this has been your current approach). All CMYK work should be evaluated by the eyedropper/info palette and referenced colour swatch books for that press/stock. So visual editing of CMYK or Greyscale images is never that "accurate" anyway. Every time you open an untagged RGB image you will be asked to identify what colour space it came from. Choose the appropriate profile and CONVERT the colours to your working space colours. Actual image values will change, but the images overall colour will be correct. THIS MEANS THAT YOU WILL NEED GOOD PROFILES OF ALL YOUR INPUT DEVICES. YOU WILL ALSO HAVE TO MAKE SOME EDUCATED GUESSES...if the image has no profile you can guess the colour condition, based on where it came from (Mac or PC etc). Untagged CMYK and Greyscale will open with no colour management. * Profile Mismatch: For RGB I would use "Ask When Opening". You can choose to convert, or not! Since the ICC tag is listed - you can write it down, cancel opening the file and change your RGB workspace to match. When you reopen the file, the colour space will match the file and it will simply open...this is colour management at it's best! Or, you could simply decide to convert the images colour values from the tagged colour space to the working space you are using...colours will change, but it will now match your preferred colour editing space. Once again this is how colour management is meant to work. CMYK would be set to "Ask When Opening". If possible try to match CMYK working spaces so that no profile mismatch takes place (as above). If this is not possible, I would never convert colours. The same rules apply to Greyscale files. Actual image values are usually better than "correct" previews for pre separated print images. These profile handling options require initial manual effort for legacy or non ICC tagged files. You pick a source and destination profile, a rendering intent and whether to use black point compensation. This little bit of extra effort gets the file into Photoshop in the best way for your work flow. I prefer to play things safe and judge each image on a case by case basis. Once you have the file tagged/saved, the whole colour management process becomes simpler. _____ There is so much more left unsaid! For all this to work, you will need good profiles of all your input and output equipment. You and your associates will need to understand and embrace colour managed work flows. This is just a very brief primer on colour management, from one struggling user to another. The previous links are more detailed and knowledgeable. :) Please feel free to post with any follow ups, this is not an easy process to enter into." Hope this helps, Stephen." Time for another lie down? :-) > Ole no Moire (CMYK) testpic looks good, all colour grades show, but do > notice that on 50% grey block the eyedropper reading is 148-148-148 RGB, > 43-32-31-10 CMYK - is this right? Also notice Ole is rather lacklustre > with 'Enable Monitor Compensation' not ticked.... hmmm, I think you're > right Shanghara Hmmm...You got me worried now because on the 50% grey block I get different readings: CMYK: 0, 0, 0, 50%. RGB: 151, 151, 154 (the readings are from the Ole No Moire from the PS7 CD). The only way I can generate CMYK values for the grey block is by converting to a CMYK color space other than my working color space. It's been a while since I opened Photoshop 5 and I really don't care to just to find out why the different numbers. <G> My advice, FWIW, is to upgrade to PS7, color management in it is a little bit easier. --/ Shangara Singh http://www.e-pixel.co.uk Adobe Certified Expert ~ Photoshop 7.0 PortfoliosOnCD for Photographers http://www.portfoliosoncd.com =============================================================== GO TO http://www.prodig.org for ~ GUIDELINES ~ un/SUBSCRIBING ~ ITEMS for SALE
