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Embedded scanner profile - is this a problem?

PostPosted: Tue Mar 29, 2011 10:12 pm
by Misty
Is there likely to be a problem with embedding the scanner profile in a scan instead of an internal profile?

When doing some test scans, I accidentally reset the "Input -> Internal" CMS setting. I noticed it when I was looking at my test scans because some of the images were marked as having the scanner's calibrated colour profile instead of the usual ECI RGB or Adobe RGB. It looks like the scanner's input profile was embedded instead of a working space.

To my surprise, however, the images looked identical to their standard display profile counterparts in Mac OS X's Preview application. Do ICC-enabled applications usually support input profiles as well as display profiles? Is there a disadvantage to doing this? It seems like keeping the internal profile could be advantageous for a master image because there isn't a 1:1 mapping between the scanner's colour space and the standard colour spaces.

Re: Embedded scanner profile - is this a problem?

PostPosted: Fri Apr 01, 2011 8:27 am
by LSI_Morales
Dear Misty,

Misty wrote:When doing some test scans, I accidentally reset the "Input -> Internal" CMS setting. I noticed it when I was looking at my test scans because some of the images were marked as having the scanner's calibrated colour profile instead of the usual ECI RGB or Adobe RGB. It looks like the scanner's input profile was embedded instead of a working space.


It happened because the internal profile was set to "none", usually the embedded profile should be the internal profile so the conversion from the input (the scanner) to the system is correctly performed. Since you had set the internal to none, it automatically embedded the scanner profile for a future conversion with a second application.

Misty wrote:To my surprise, however, the images looked identical to their standard display profile counterparts in Mac OS X's Preview application. Do ICC-enabled applications usually support input profiles as well as display profiles? Is there a disadvantage to doing this? It seems like keeping the internal profile could be advantageous for a master image because there isn't a 1:1 mapping between the scanner's colour space and the standard colour spaces.


The images looked identical because (I will speculate here) probably the Mac Preview app did the conversion automatically. In this occasion it worked for you but since you do not know which internal profile was used as well as the conversion method (rendering intent), it might have been pure coincidence.
If the application you are using later is ICC-enabled but has a different standard profile as internal (e.g. sRGB) then the gamut is smaller than AdobeRGB or ProPhotoRGB and the conversion method (rendering intent) is not the same, then you might experience a color shift.

Misty wrote:Is there likely to be a problem with embedding the scanner profile in a scan instead of an internal profile?


Basically there should not be a problem as long as you know that you have to make the conversion and use the right profiles as well as rendering intent.

Cheers

Re: Embedded scanner profile - is this a problem?

PostPosted: Thu Feb 02, 2012 4:27 am
by Shekwork
I have the same question about embedding a color profile. Even though I set the RGB color profile in Silverfast to Adobe RGB it still says the Silverfast SF_R (color target) when looking at the image and color file details in Adobe bridge. Should I just have Adobe Photoshop override the color profile to Adobe RGB to ensure no conflict with the Silverfast color target? Thanks

Re: Embedded scanner profile - is this a problem?

PostPosted: Fri Feb 03, 2012 10:32 am
by LSI_Morales
Hi Shekwork

Shekwork wrote:Even though I set the RGB color profile in Silverfast to Adobe RGB it still says the Silverfast SF_R (color target) when looking at the image and color file details in Adobe bridge. Should I just have Adobe Photoshop override the color profile to Adobe RGB to ensure no conflict with the Silverfast color target?


The conversion to Adobe RGB is only made when working with modified files (not raw files). If you are scanning raw files, no color conversion is taking place (because is a raw file), embedding the scanner profile (and not adobe RGB) helps the next program identify the source.

By ignoring this you are more or less letting your application randomly interpret colors.

Kind regards

Re: Embedded scanner profile - is this a problem?

PostPosted: Fri Feb 03, 2012 8:47 pm
by Shekwork
I'm still confused since I'm scanning in .tif format should I just have photoshop override Silverfast since the scans are directly imported into photoshop or should I just leave the existing embedded color profile from Silverfast which is set to Adobe RGB?

Re: Embedded scanner profile - is this a problem?

PostPosted: Tue Feb 07, 2012 2:06 pm
by LSI_Morales
Hi there

Shekwork wrote:I'm still confused since I'm scanning in .tif format should I just have photoshop override Silverfast since the scans are directly imported into photoshop


So, Are you scanning in tif saving the files and then opening them afterwards in photoshop, or are you opening SilverFast directly from photoshop and sending the scans directly without saving them?

If its the former option you should accept the embedded profile when opening the file.

If it is the latter you should probably leave the CMS settings as they are and have photoshop configured to have the profile you want to work with.

Cheers

Re: Embedded scanner profile - is this a problem?

PostPosted: Sun Feb 19, 2012 1:38 pm
by feldhaim
For master files I'd rather NOT convert to AdobeRGB or any other non-Scanner colorspace.
If you really need a different working space use a wide gamut space which contains all the colors your scanner gamut has.
If you use a gamut visualization softeware you most likely will see colors from the scanner gamut which are not represented in AdobeRGb which will result in a loss of colors your scanner and film are able to reproduce.
I'd rather keep the scanner profile for a master file and use a wide gamut working space in Photoshop like ProphotoRGB to minimize color loss.
Who says in future we might not have printers which can show all these great colors?
And especially when working with 16 bit/channel files color banding won't be a problem when using large color spaces.