What does an ICC profile change?

Each color lab uses an icc profile. My main pro lab uses SRGB. Another uses Adobe 1998. Also, each ink jet printer has a profile. You should know what profile your printer uses as well as any outside labs you use. I also recommend running the Adobe Gamma. If you use a pro lab get a kit from them for setting up your monitor to match their output.

Craig Flory

Each device has its own color language. The profile simply tells the input device what language it is speaking so it can compensate. That way the monitor displays it the way the scanner says it should, and the printer prints to look like it does on the screen.

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– Alan Justice

"Philip Procter" wrote in message

When I change to a different profile (say from RGB 1998 to the profile that came with my Canon) what is changing: the screen image, the printer image or both?

I’ve tried taking a portrait and swapping profiles but I don’t see any difference in the image on monitor or on paper.

Philip

When I change to a different profile (say from RGB 1998 to the profile

that came with my Canon) what is changing: the screen image, the printer image or both?

The RGB numbers are changed … in a perfect world, they are changed so that what you see on the screen will look as close as possible to what you see on the print.

I’ve tried taking a portrait and swapping profiles but I don’t see any

difference in the image on monitor or on paper.

Enable soft proofing and you should see the differences between what can be displayed on the screen and the reduced brightness of the print. You especially see this if you enable ‘simulate:paper white’.

Also, if you have an image with bright reds and oranges (for example) or just a test file with these colors you can see the differences between say AdobeRGB and sRGB in the more saturated colors … just do image > mode > convert to profile and then ctrl-z back and forth to see this.

When I change to a different profile (say from RGB 1998 to the profile

that came with my Canon) …

I assume "RGB 1998" is AdobeRGB, right? You should distinguish between different classes of profiles … AdobeRGB and sRGB (and others) are "working space" profiles, abstract profiles that are grey-balanced and defined for a particular gamut width. So you would edit your files in those. When you look at the file on the screen it’s being adjusted by your monitor ICC profile on the fly so the colors represented by the RGB values match your specific monitor. This monitor profile is a "device specific" profile (as opposed to the non-device specific working space profiles, which don’t match a specific device). When you print with an ICC profile you’re translating the RGB values again, this time to a device-specific printer profile that hopefully translates the numbers so the print looks as close to the monitor as possible. You can actually read off these translated numbers if you have a file open and apply a soft proof (view > proof setup > custom) and open the Info palette and right-click on the second eyedropper and change it to ‘proof color’.

If this is unclear here’s a good link explaining the basics of translating the RGB triplets to different values for different devices using the ICC profiles …
http://www.creativepro.com/story/feature/13605.html

Bill

Bill Hilton wrote:

When I change to a different profile (say from RGB 1998 to the profile

that came with my Canon) what is changing: the screen image, the printer image or both?

The RGB numbers are changed … in a perfect world, they are changed so that what you see on the screen will look as close as possible to what you see on the print.

I’ve tried taking a portrait and swapping profiles but I don’t see any

difference in the image on monitor or on paper.

Enable soft proofing and you should see the differences between what can be displayed on the screen and the reduced brightness of the print. You especially see this if you enable ‘simulate:paper white’.
Also, if you have an image with bright reds and oranges (for example) or just a test file with these colors you can see the differences between say AdobeRGB and sRGB in the more saturated colors … just do image > mode > convert to profile and then ctrl-z back and forth to see this.

When I change to a different profile (say from RGB 1998 to the profile

that came with my Canon) …

I assume "RGB 1998" is AdobeRGB, right? You should distinguish between different classes of profiles … AdobeRGB and sRGB (and others) are "working space" profiles, abstract profiles that are grey-balanced and defined for a particular gamut width. So you would edit your files in those. When you look at the file on the screen it’s being adjusted by your monitor ICC profile on the fly so the colors represented by the RGB values match your specific monitor. This monitor profile is a "device specific" profile (as opposed to the non-device specific working space profiles, which don’t match a specific device). When you print with an ICC profile you’re translating the RGB values again, this time to a device-specific printer profile that hopefully translates the numbers so the print looks as close to the monitor as possible. You can actually read off these translated numbers if you have a file open and apply a soft proof (view > proof setup > custom) and open the Info palette and right-click on the second eyedropper and change it to ‘proof color’.

If this is unclear here’s a good link explaining the basics of translating the RGB triplets to different values for different devices using the ICC profiles …
http://www.creativepro.com/story/feature/13605.html

Bill

When dealing with ICC profiles, PS has its own lingo such as attach, assign, convert and soft proof (and more?). By "change to a different profile", the original poster could have meant one or more of these. While the lingo are well explained in the PS manual, they are scattered all over the place. PS should also publish a dictionary or an encyclopedia. Sigh.