BBP color profile support...

[olearydj]

I would like to try the new AboutDigicam profiles for the 1dmk2 but I'm confused by the bbp color profile setup. I normally use auto embed sRGB / aRGB and everything works just fine. The images show Adobe RGB (the color space I shoot in) and the colors appear correct.

I assume I'm supposed to turn off auto embed and choose the appropriate AboutDigicam profile, but this feels wrong and produces results to match.

What is the correct way to set this up?

[Chris Breeze]

The profiles don't affect the converted data, what they do is describe the colorspace of the converted data. This means you need to enable color management in BBPro and select a suitable monitor profile in order to see the effect. You also need to turn off the auto profile options in the raw preferences and specify the profile explictly.
For normal raw conversion you should use the non-linear profile and for linear conversion use the linear profile. Unfortunately the Canon SDK can't produce raw previews when using linear conversion and so this has to be simulated and doesn't give a very accurate idea of the final result.

[olearydj]

Maybe I'm confused. I'm use to seeing a monitor profile, a camera color space (AdobeRGB in my case), a destination color space (sRGB, for example), and a camera profile. When using C1 to do the raw conversions I have to specify each of these - the profile is used to render a calibrated version of the image in the desired destination color space.

BBP reads the camera color space correctly from exif datea. It also allows me to specify the monitor profile. But instead of specifying both the destination color space and the camera profile these seemed to be combined in the "embed color profile in images for normal/linear raw conversion" boxes.

Am I missing something or just misunderstanding?

[Chris Breeze]

The colorspace of the converted file is determined by the colorspace setting in the raw conversion dialog - either sRGB or AdobeRGB. You can either embed the standard sRGB or AdobeRGB color profile in the converted image or use a profile for your camera instead. The camera profile should give a more accurate description of the colorspace of the converted image than the standard AdobeRGB profile. This means that for the best results you need a camera profile specific to your camera model (or a custom one for your individual camera) which has been created for the characteristics of the raw converter you use.

[olearydj]

Ok, Chris, I follow. I set the Preferences / Raw Conversion / Profile for my 1dmk2 to the About Camera non-linear profile. Then I converted and chose embed profile AdobeRGB. The result was a 16 bit AdobeRGB TIF converted from RAW using the 1dmk2 profile supplied by AboutDigicam.

Let me say that I find this setup very unintuative in BBP. I have set up color management in Photoshop, ACDSee, Capture 1, and Bibble without any problems. I still feel like BBP muddles the distinction between a camera profile and a color space.

Also, it seems odd that the color space selector in the actual conversion dialog would default to the profile chosen for the camera. I had to change this to AdobeRGB. I assume that is a bug.

Thanks for your help sorting this out.

[jrsforums]

OK....I'm a little confused by the above and the way BB Pro works. I have a new 20D. My work flow would be to creat images which I will place on my website (not via BB HTML), print on Qimage, or process selected ones on Photoshop.

In preferences, indicate the respective "20D True Color..." profile and turn of auto embed. When I go to convert, the "Output Settings" profile indicates the respective 20D profile dependent on whether I select Normal or Linear.

When doing this, what will the color space be? For Qimage or PS, I assume it could be sRGB or AdobeRGB (PS preferring the ARGB), but for the web, I think I want sRGB. If I select either of the RGBs, will the 20D profiles have been taken into effect on conversion or do I need to specify the 20D profile (which one???) in Qimage or PS?

Chris, I am sure it is just my lack of familiarity with this, but I would appreciate if you could clear up the settings and actions for each of these cases....web, Qimage, PS...incuding the Qimage/PS actions/settings (don't need specific views, just verbally what needs to be done.)

Thanks....JOHN

[Chris Breeze]

The color space setting in the raw conversion dialog affects the way the raw file is converted and can be set to sRGB or AdobeRGB. Embedding a color profile in the image does not affect image data or conversion process in anyway. The color profile is a description of the color space of the file and is read by color managed applications to interpret the colors in the image more accurately. If the image contains an appropriate color profile and is viewed or printed by a color managed app using an appropriate output color profile the results should be near identical.

If you convert a 20D raw file with the color space set to AdobeRGB and embed the AdobeRGB profile then color managed apps should be able to display it correctly. The AboutDigicam non-linear profile is an alternative to using the AdobeRGB profile and tells the app reading the image to interpret the colors slightly differently - whether this produces better results than embedding the AdobeRGB profile is a matter of personal taste. You can buy different profiles which give the image a different "look" e.g. increase the saturation to give a Velvia look.

[jrsforums]

Thank, Chris. I think I have this, but just want to be sure. So let me state it in my words...pls correct or confirm....

Color space is what the raw sensor data is converted into, by either the camera or BB, and this is either RGB or AdobeRGB. The embedded profile tells the post processing software (PSCS, Elements, Qimage, etc) how to interpret the data. This profile can be the standard sRGB, AdobeRGB, or a specific profile for your camera (this could be based on either RGB or AdobeRGB). Only one profile is embedded.

In BB, the Color Space is defined in the Raw conversion screen and the embedded profile is defined in preferences. I assume if both RGB and AdobeRGB Auto embed are selected, only one will be embedded dependent on the color space selected in raw conversion. (If an AboutDigicams profile is used should you not select any Auto embeds?)

If no profile is embedded, you will have to define the icc profile for the postprocessing sw to use.....sRGB, Adobe, or specific profile.

I hope I am not prolonging the agony here....just trying to get this clear.

Thanks again.....JOHN

[Chris Breeze]

Yes, that's correct.

If you don't embed a color profile in the converted image color managed apps won't know what to use and will either assume one (which may be incorrect) or prompt you to specify the color space.