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Posted: Mon Apr 04, 2011 4:31 pm
by leeharper_admin
Jacob Rus just posted (to the ACT list) about an L* ICC profile that somebody had recommended to him; information about using it (and the file itself) is available from here: http://www.libraw.org/articles/displaying_L_channel_in_Photoshop.html.

I've just installed it, and it's great!

I'm thinking that for the standalone app, LittleCMS would make adding this to CM4 fairly straightforward - no?

I am thinking that using this L* profile (or something similar) to preview the image in B/W would be very useful in CM4 - both for B/W conversion workflows, and when working in the 'Tone' tab.

Download the ICC profile and let me know what you think of it ;)

Cheers,
Lee.

Posted: Mon Apr 04, 2011 4:42 pm
by ggroess
But...Is this just not converting the L channel to match a RGB composite?  The difference is when you switch on the "Show Colors" 

Since Lab calculates the L channel differently than the RGB composite I would expect differences.  If I use channels and show the data in the channels as is; when I copy channels and apply, then set the resulting layer to a luminosity layer am I not just fooling myself ahead of time so to speak...

I would say to stay true to the discussion we have had so far on this; you should be able to assign the profile in CM4 but making it the default display might be a bit arbitrary. 

I'm not sure I see the value if we tackle each channel as a separate problem using the Zone system pins.
I must be missing something...
Greg

Posted: Mon Apr 04, 2011 6:26 pm
by mikemeister_admin
Hi Greg,

Good call about the channel blending :) Things start to get interesting though when we start working with the zone system and L* gamma: http://stonerosephotos.com/blog/?p=675

I just found this article, so I've only scanned through it quickly, but it seems really interesting and might have a bearing on the zone system aspect of the workflow/app.

Lee.