simon_garrett's profile

10 Messages

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352 Points

Tue, Apr 21, 2015 10:30 PM

Lightroom 6: Rendering problem with saturated colors using Graphics Processor

Possible issue with use of graphics processor: rendering in Develop Module of wide-gamut colours in error, LR6, problem goes away when "Use Graphics Processor" unchecked, problem didn't occur in LR5.x

Graphic card: NVidia GeForce GTX 550 Ti, latest drivers (350.12 but also occured with 340.52). Win 7 Home Premium, 64-bit, LR6, CC version.

Problem is this: with a wide-gamut monitor, in Develop Module, highly saturated blues are the wrong tone. They have to be VERY wide gamut: the problem occurs only with blues outside Adobe RGB gamut. These blues are rendered OK if "Use Graphics Processor" is unchecked. Obviously, in Library module this isn't a problem as colours are limited to Adobe RGB anyway.

Also, even in Develop Module, colours are OK on the 2nd Lightroom monitor window, wrong only on the main Lightroom monitor. If I move the main window to the other monitor, then it's that monitor that's now wrong. In other words: it doesn't depend on the monitor (one's HP, one's Eizo) nor on the calibrator s/w (one's calibrated with iProfiler, one with ColorNavigator, both creating v2 icc profiles). The false tone rendering appears only on the main LR window and only in develop module, and only when "use Graphics Processor" is checked.

Not a huge problem, but appears to me to be a bug.

PS - Test image supplied that shows the problem. The blue blob bottom left, which is RGB 0,0,255 in ProPhoto RGB renders OK without the graphics processor but not with it on. Perhaps the issue is because (0,0,255) in ProPhoto isn't a real colour? In which case, I wonder why software rendering displays a reasonable attempt, but the graphics processor software doesn't? Perhaps the graphics processor engine doesn't manage unreal colours quite as gracefully as the software rendering.

If the problem is confined to ProPhoto "colours" outside the range of real colours, clearly it's not really an issue.

Responses

1 Message

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80 Points

6 y ago

Windows 8.1, Dell U2711 profiled with X-Rite i1 Display Pro and a GeForce GTS 450. Lightroom CC 2015.1.1 with ACR 9.1.1.

I'm suffering the same discrepancies between Library/Develop modules from time to time, particularly with red tones. I have tried a secondary display window on the same calibrated monitor showing the loupe view and checked the inconsistency in tones.

Still trying to replicate the ¿bug? to know what is triggering it.

2 Messages

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72 Points

6 y ago

I am currently trialing Lightroom 6/2015.1 ACR 9.1 and I have this exact problem. My display is calibrated but LR has color problem with Graphics Processing enabled when in Library view. Oddly, when I just compare an unedited file, the 2nd image (GPU on) faithfully renders the image when I use Windows Explorer previews as a reference. So in my case, enabling GPU processing actually fixes the color issue in the Develop mode, but keeps it in Library mode.

How do I fix this?

I am on Windows 10 Pro, Pentium G3258, 16GB RAM
Graphics Processor Info:
GeForce GTX 960/PCIe/SSE2
Check OpenGL support: Passed
Vendor: NVIDIA Corporation
Version: 3.3.0 NVIDIA 355.60
Renderer: GeForce GTX 960/PCIe/SSE2
LanguageVersion: 3.30 NVIDIA via Cg compiler

2 Messages

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70 Points

6 y ago

Problem solved with upgrade to Windows 10
Don't ask me why !!

2 Messages

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72 Points

6 y ago

Found the solution on this thread:

http://www.dpreview.com/forums/thread...

Basically add an sRGB icm profile in Windows Color Management and problem is solved. My profile was set to an icm provided by the manufacturer (AOC G2460)