Luminous Landscape Forum

Raw & Post Processing, Printing => Printing: Printers, Papers and Inks => Topic started by: Craig P on March 23, 2007, 06:32:54 pm

Title: Beginner question on color space
Post by: Craig P on March 23, 2007, 06:32:54 pm
Forgive my lack of knowledge - If my Ilford ICC requires that the images are in RGB and all my files are sRGB, what's the best way to handle that in Lightroom?  Do I need to make new copies of everything I want to print, saving with the RGB colorspace?  I did this in Elements and while the print matched what was on the screen, the image had a color shift when it went from sRGB to RGB (a magenta shirt became a shade of red).  Very confused.
Title: Beginner question on color space
Post by: digitaldog on March 23, 2007, 06:50:25 pm
Quote
Forgive my lack of knowledge - If my Ilford ICC requires that the images are in RGB and all my files are sRGB, what's the best way to handle that in Lightroom?  Do I need to make new copies of everything I want to print, saving with the RGB colorspace?  I did this in Elements and while the print matched what was on the screen, the image had a color shift when it went from sRGB to RGB (a magenta shirt became a shade of red).  Very confused.
[a href=\"index.php?act=findpost&pid=108365\"][{POST_SNAPBACK}][/a]

Not sure I understand what you're doing. Illford being a paper you're using in some printer OR you're sending out files to a lab using an Illford printer?
Title: Beginner question on color space
Post by: Craig_P on March 23, 2007, 09:31:47 pm
Quote
Not sure I understand what you're doing. Illford being a paper you're using in some printer OR you're sending out files to a lab using an Illford printer?
[a href=\"index.php?act=findpost&pid=108367\"][{POST_SNAPBACK}][/a]

Printing on an Epson R220 and using the downloaded Ilford ICC.  I've chosen ICM and No Color Adjustment in the Epson Properties box.  I've got some gaps in my understanding - Why use sRGB (which appears to be default setting for cameras) when printing uses aRGB?  I should just go back to film.
Title: Beginner question on color space
Post by: dkeyes on March 23, 2007, 10:26:43 pm
Quote
Printing on an Epson R220 and using the downloaded Ilford ICC.  I've chosen ICM and No Color Adjustment in the Epson Properties box.  I've got some gaps in my understanding - Why use sRGB (which appears to be default setting for cameras) when printing uses aRGB?  I should just go back to film.
[{POST_SNAPBACK}][/a] (http://index.php?act=findpost&pid=108378\")

Craig,
It's all RGB color space just different versions if you will. Some RGB spaces favor blues some favor reds some have bigger gamuts than the printer can print (like ProphotoRGB). I don't know the difference between aRGB (Adobe RGB?) and sRGB. If aRGB is Adobe RGB both these spaces are similar enough that you should get the same overall color.
Go to Joseph Holmes website. He has all the info on RGB color space.
 [a href=\"http://www.josephholmes.com/profiles.html]http://www.josephholmes.com/profiles.html[/url]
Go to FAQ's and look at "How do you use RGB spaces..." talks about RAW conversion etc.

The biggest differences when printing are what driver you use (Epson, or custom RIP) and ICC profiles for the paper. Sounds like you have the right ICC profile.

Hope this helps, this is a much bigger topic than I can talk about. Maybe some of the more technical folks will respond as well.

- Doug
Title: Beginner question on color space
Post by: Craig_P on March 23, 2007, 10:52:43 pm
Quote
Craig,
It's all RGB color space just different versions if you will. Some RGB spaces favor blues some favor reds some have bigger gamuts than the printer can print (like ProphotoRGB). I don't know the difference between aRGB (Adobe RGB?) and sRGB. If aRGB is Adobe RGB both these spaces are similar enough that you should get the same overall color.
Go to Joseph Holmes website. He has all the info on RGB color space.
 http://www.josephholmes.com/profiles.html (http://www.josephholmes.com/profiles.html)
Go to FAQ's and look at "How do you use RGB spaces..." talks about RAW conversion etc.

The biggest differences when printing are what driver you use (Epson, or custom RIP) and ICC profiles for the paper. Sounds like you have the right ICC profile.

Hope this helps, this is a much bigger topic than I can talk about. Maybe some of the more technical folks will respond as well.

- Doug
[a href=\"index.php?act=findpost&pid=108383\"][{POST_SNAPBACK}][/a]

Thanks Doug,
When I was using the straight sRGB file, I was getting a yellowish cast to my prints.  Upon reading that I should be using Adobe RGB space with the Ilford icc, I saved a version as such.  Not only was there a color shift, but the aRGB file had more pop/saturation - almost too much.  I will look at the Holmes website - thanks again.