Lightroom 2.3 on Mac clips dark shades of grey

[sunlit]

mac os x leopard 1'.5.7, lightroom 2.3 and photoshop cs4.
In Lightroom a photo with dark shades of grey (RGB from 6-6-6 and closer to complete black) shows complete blackout in those dark grey areas, i.e. they are not visible.
Same photo opened in PHotoshop shows perfect view of those shades of grey.
I wonder - why?
TO be honest I must say that apart from photoshop, all other viewers on mac similarly clip dark areas - including apple preview, safari browser, and iphoto.
I attach the original file that has such dark areas.

 

[Victoria Bampton]

Hi Sunlit, welcome to the forum!

How are you calibrating your monitor - and what kind of monitor?

 

[sunlit]

Hi Vicroia!
I calibrate my Apple Cinema HD 3'" using x-rite colormunki spectrophotometer.
I guess the matter lies in the way mac os treats images, since apart from photoshop (and photoshop bridge) all other image viewers I tried do clip dark greys.
You can try a simple test - open the image I attached in Lightroom and in Photoshop side by side - on my machine I see huge difference.
I must also add that I do not see this difference in Windows Vista using different computer, but THE SAME cinema hd display and using the same image in same applications (windows versions of course)

 

[sunlit]

Hi Victoria
thanks for replying
I use Cinema HD 3'" and I calibrate it with x-rite colormunki spectrophotometer.
You can try a simple test - use attached image in my original post, and open it side by side in Lightroom and Photoshop (on a mac computer). I see huge difference on my mac book pro.
I don't see this clipping behavior in Windows vista, using a different computer with THE SAME cinema hd display.
I guess something is wrong with the way mac os displays images, and somehow only photoshop overrides this, since all other viewers on my mac do clip the dark greys.
In windows both lightroom and photoshop display the image identically.

 

[sunlit]

you can also try another very simple test
in Photoshop use a brush of RGB 6-6-6, 1'-1'-1', 15-15-15, you get the ided
and paint something with it on a black background
In photoshop on my display I can discern even RGB 1-1-1 over a black RGB '-'-' background. Then save the file as jpg and import it to Lightroom.
I did a quick test and lightroom only shows beginning from somewhere like 1'-1'-1',
and starting from 6 and lower is completely invisible. Comments?

 

[sunlit]

Again I must qualify here that this does not seem to be lightroom bug, it is rather a bug in mac os rendering, however Photoshop manages to override it somehow, and display all shades of grey correctly. So you may be able to shed some light on the issue.

 

[Victoria Bampton]

Does your calibration software give you a choice between Matrix profiles and LUT profiles? If so, I'd bet you're currently using an LUT profile and Lightroom will be happier with a Matrix profile. That will likely solve the problem.

Photoshop overrides it because it uses ACE - it's own color engine - whereas all of the other programs including Lightroom uses ColorSync on Mac and ICM on Windows.

 

[sunlit]

yes, the issue seems to be with my calibration process! I do have the option to disable LUT, it gives slighter better situation with dark grey colors, but still nothing below RGB 6-6-6 is visible. I will raise the issue with x-rite suport, thank you very much for your assistance!

 

[Victoria Bampton]

That's a great start. Do let us know what they say! I have a feeling they'll blame ColorSync somehow!

 

[sunlit]

By going through all the profiling options available in colormunki software (actually these options appeared only recenlty with 1.1 release, they were not there before at all!)
I found a way to get a good profile for my monitor on mac. To achieve this I disable use of DDC and videocard LUT, and also use ICC profile version 2.', and not 4.' which is the default with colormunki (version 2 was not even available in previous release of the software).
After all that fiddling I am now happy with a perfect profile, showing almost complete gamut from black to white!
Thank you very much for assistance and I am sorry to post the issue here, which turned out to be not at all related to Lightroom.
Thank you again
Alexander

 

[sunlit]

now in my sample picture - which is actually me rowing away in a boat on a lake, I can see the folds of my tee-shirt, and the area of my body in shade, which is RGB 6-6-6 and darker.

 

[Brad Snyder]

Thank you very much for assistance and I am sorry to post the issue here, which turned out to be not at all related to Lightroom.

But in fact, I believe the changes to the CM drivers were prompted by unhappy Lr users, like yourself.

 

[Denis Pagé]

Being a ColorMunki user like Brad, I found your thread informative and you made me aware of the 1.1 update...