Can someone explain color managment profiles?

[toddb]

I'm getting closer to understanding color management, but I just want to solidify my understanding. When editing in the digital world, I'm finding that you can tweak the photo allot, however, if you are not seeing the real colors, your going backwards and probably doing more damage then good.

Profiles. I have a profile for my Viewsonic VX800 LCD. When I load a picture in photoshop 7, it ask me if I want to use the camera's sRGB profile, or convert it to my VX800 profile (or discard the info all together). When I convert it to my VX800 it looks good and true (or I think it's true). If I try and quit Photoshop it ask me to save...this is where my question lies. When I save after converting my color profile of a certain pictures, does that mean anything that opens it will use that profile?

My understanding is that the bits are not changed when changing profiles. It just allows whatever is reading to interpret the colors correctly....is that correct? What if I have a certain printer profile...like for example I print my pictures at Costco allot (can't beat 19 cents) and someone posted a profile for the printers they use. Do I need to save the file after tweaking in photoshop with the profile I want to print to (and if so how)?

Thanks for any info that can help my understanding of this. I'm real close in purchasing the Syder ColorVision from B&H. Spyder Colorimeter Photo Suite Pro (LCD/CRT) (http://www.bhphotovideo.com/bnh/controller/home?O=cart&A=details&Q=&sku=241679&is=REG)

[Dave I]

As I understand it (and I get prints very very close to what I see on screen).

When you CONVERT to a new profile, you're actually changing the values of the pixels.

I normally work in Adobe RGB, but just before I print, I convert to my printer's profile (BJ Color Printer Profile 2000, for my Canon S9000 inkjet), and then print it. If I forget to convert to the printer's profile, the colors look all washed out. This is because the printer's color gamut is wildly different from AdobeRGB

Another thing. If I go to View|Proof Setup|Custom|Profile - BJ Color Printer Profile 2000 (same as my printer), and then make sure View|Proof Colors is checked, I get much more accurate colors.

Also, use the Adobe Gamma gadget in the control panel to make sure your monitor is pretty close to accurate.

[Roger_Cavanagh]

Todd,

It's not recommended that you should use your monitor profile as a working space in Photoshop. Once you have correctly profiled your monitor and specified the profile in the system, then you should just use the sRGB profile that your images are already tagged with.

Photohsop take the monitor profile into consideration when it displays images, but if you either ASSIGN (tags the image with the profile, but does not change any image data) or CONVERT (changes the image data and tags with the new profile) to your monitor space, your images may not look right on someone else's system.

Images contain data about colours with numbers for the mixture of red, green and blue for each pixel. The same numbers may look different in different colour space.
When you assign a profile you are choosing how the colour numbers should appear. You can play around in Photoshop and assign different colour spaces using Image>Mode>Assign Profile. The preview will show how the colours will change.

When you convert to a colour space, the existing colour numbers are modified so that the colours will look the same in the new space. Since not all colour spaces are the same size, colours that are outside the gamut of the new space will be changed so fit, and may be noticeably different.

I've some useful links on colour management here:

http://www.rogercavanagh.com/helpinfo/10_colourmanagement.htm

Regards,

[toddb]

Thank you, this helps alot.