Lightroom 6 GPU Acceleration bug causing color contrast issues?

Rayn · 05-31-2015, 11:54 AM

I've made a short video of the issue here:

Youtu.be

Basically, I've been going crazy for days trying to figure out why all my images look so contrasty and un-natural all of a sudden. What was even more puzzling was that when I used the "bypass LR processing" or the before/after comparison, the "original" image looked fine, even though I've done absolutely ZERO processing on the image in LR. It happens on both Pentax DNG and TIFF files (didn't try JPEG's yet). It appears to be a bug in LR 6, as it only happens with GPU acceleration turned on.

Last edited by Rayn; 06-01-2015 at 12:29 PM.

stevebrot · 05-31-2015, 12:17 PM

Do you have a motherboard-based GPU or a separate video adapter? Any chance the problem depend on the tech used in the GPU?

Steve

wombat2go · 05-31-2015, 12:36 PM - **1 Like**

The Nvidia driver for the GPUs here has facility in its UI to over-ride the application and o/s settings for color, gamma, any-aliasing etc.
There are sliders along with buttons on each pane to "Reset Hardware Defaults"

Rayn · 06-01-2015, 12:26 PM

And it's back...

I've reset the GPU control panel customizations, and that seemed to fix the issue, but it's back now.. and I'm clueless as to why.

Any help is appreciated.

Rayn · 06-02-2015, 03:06 AM

Originally posted by stevebrot

Do you have a motherboard-based GPU or a separate video adapter? Any chance the problem depend on the tech used in the GPU?

Steve

I have a GTX 660 2GB, a fairly powerful and new Nvidia PCIex card. Latest drivers/win patches installed.

wombat2go · 06-02-2015, 05:11 AM - **1 Like**

Originally posted by Rayn

and that seemed to fix the issue, but it's back now..

The Nvidia driverGUI on X server generates a file "xorg.conf"
I presume something similar on Win.
After a change is done on the Nvidia GUI, it is necessary to press "Save to X config file", otherwise it can revert to the settings in that file.

Also if your Nvidia driver is not the latest version fully supporting your GPU, the GUI might not be able to fully complete the "xorg.conf"
( I recall having to to edit that file manually to get Truecolor working persistently on the Quadro)

Drivers | GeForce
https://forums.geforce.com/

Rayn · 06-03-2015, 03:19 AM

Originally posted by wombat2go

The Nvidia driverGUI on X server generates a file "xorg.conf"
I presume something similar on Win.
After a change is done on the Nvidia GUI, it is necessary to press "Save to X config file", otherwise it can revert to the settings in that file.

Also if your Nvidia driver is not the latest version fully supporting your GPU, the GUI might not be able to fully complete the "xorg.conf"
( I recall having to to edit that file manually to get Truecolor working persistently on the Quadro)

Drivers | GeForce
https://forums.geforce.com/

I reinstalled the GPU drivers and lightroom, and it now appears to be working fine again.
Thanks for you help

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05-31-2015, 12:17 PM	#2
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Do you have a motherboard-based GPU or a separate video adapter? Any chance the problem depend on the tech used in the GPU? Steve

05-31-2015, 12:36 PM - 1 Like	#3
wombat2go Veteran Member Join Date: Jan 2010 Location: Michigan Photos: Gallery Posts: 2,207	The Nvidia driver for the GPUs here has facility in its UI to over-ride the application and o/s settings for color, gamma, any-aliasing etc. There are sliders along with buttons on each pane to "Reset Hardware Defaults"

06-01-2015, 12:26 PM	#4
Rayn Forum Member Join Date: Feb 2014 Location: Zagreb Posts: 73 Original Poster	And it's back... I've reset the GPU control panel customizations, and that seemed to fix the issue, but it's back now.. and I'm clueless as to why. Any help is appreciated.

06-02-2015, 03:06 AM	#5
Rayn Forum Member Join Date: Feb 2014 Location: Zagreb Posts: 73 Original Poster	Originally posted by stevebrot Do you have a motherboard-based GPU or a separate video adapter? Any chance the problem depend on the tech used in the GPU? Steve I have a GTX 660 2GB, a fairly powerful and new Nvidia PCIex card. Latest drivers/win patches installed.

06-02-2015, 05:11 AM - 1 Like	#6
wombat2go Veteran Member Join Date: Jan 2010 Location: Michigan Photos: Gallery Posts: 2,207	Originally posted by Rayn and that seemed to fix the issue, but it's back now.. The Nvidia driverGUI on X server generates a file "xorg.conf" I presume something similar on Win. After a change is done on the Nvidia GUI, it is necessary to press "Save to X config file", otherwise it can revert to the settings in that file. Also if your Nvidia driver is not the latest version fully supporting your GPU, the GUI might not be able to fully complete the "xorg.conf" ( I recall having to to edit that file manually to get Truecolor working persistently on the Quadro) Drivers \| GeForce https://forums.geforce.com/

06-03-2015, 03:19 AM	#7
Rayn Forum Member Join Date: Feb 2014 Location: Zagreb Posts: 73 Original Poster	Originally posted by wombat2go The Nvidia driverGUI on X server generates a file "xorg.conf" I presume something similar on Win. After a change is done on the Nvidia GUI, it is necessary to press "Save to X config file", otherwise it can revert to the settings in that file. Also if your Nvidia driver is not the latest version fully supporting your GPU, the GUI might not be able to fully complete the "xorg.conf" ( I recall having to to edit that file manually to get Truecolor working persistently on the Quadro) Drivers \| GeForce https://forums.geforce.com/ I reinstalled the GPU drivers and lightroom, and it now appears to be working fine again. Thanks for you help