05-08-2018 07:41 AM
Thanks for confirming that.
My questions are:
1) Is it possible to Lenovo is providing some kind of 'not 100%' Dolby Vision support by using an 8-bit panel just like what Apple have done?
2) How do we know that Windows doesn't already support Dolby Vision with these laptops if there are not games/video players on Windows 10 that support displaying things with it at the moment? Isn't it possible that a few months or years down the line YouTube or Netflix or some MS Store game is launched that support Dolby Vision and viola we've already got the laptop and OS to support it.
Or am I missing something?
05-08-2018 07:44 AM
OK I wasn't aware that local dimming isn't required for HDR. I would have thought that it is because if there's a movie scene with very dark and very bright objects then the display needs to be able to display them both at the same time. Maybe I was wrong then.
05-08-2018 07:48 AM - edited 05-08-2018 07:50 AM
Maybe you are right and Lenovo is trying to sell us "fake" DolbyVision like Apple with 8bit. But then you need at least FRC (Dithering). To play the full colorrange the hostsystem needs to drive the image with 10bit or even 12bit. Then the panel can output this with 8bit + FRC. Not the best solution but better than now. At the moment the max we can get is 8bit without any dithering. So no DolbyVision or HDR is possible because you are still limited to SDR Colorrange. Results are limited values in gradients and banding. So we dont have the benefits of HDR.
05-08-2018 07:52 AM
Hmm maybe look up the panel's model from the EDID (it's made by Au Optronics) and search around to see what it actually supports? I'm not sure whether the bit-depth is goverened by the panel and/or the driver board though.
Back to the HDR thing, the reason for my understanding is when one takes a 'HDR' photo with a smartphone it takes 2 images with different exposures to capture both bright and dark scenes, therefore I though it was more to do with local dimming to get the lighting contrast rather than the colour. Maybe I was wrong.
05-08-2018 08:01 AM
No, you are right. But HDR Photo is something else than HDR Videosignal. HDR Photo is merging two images with different exposures to one. HDR Videosignal covers more colors, values and do own more levels for contrast (is dynamic with dolbyVision)
I cant find any good information about the AU Optronics Panel, still too new.
05-08-2018 08:16 AM
Ahh OK thanks for the clarification.
Btw I'm surprised a Lenovo tech support person hasn't jumped in to help on this topic. I was hoping someone would at least say Yes it does, here's how customers can test it, and point us to a DV test application or something.
I draw comfort from the fact that they've released the new display INF drive that "adds support for Dolby Vision", which at least shows that they have done something.
05-08-2018 10:07 AM
05-08-2018 11:10 AM - edited 05-08-2018 11:14 AM
Did i miss something? Where is the inf file adding DolbyVision?
But they all use 8bit+FRC and HostSystem is driving Display as at least 10bit, Display just converts the Data to 8bit (with dithering). You know certification for DolbyVision? So, at the moment its totally false advertisment. Lenovo doesnt even use FRC thats why Windows still says "8bit". To use full colorrange, windows have to drive the display at least at 10bit. In 8bit (without any dithering) you cant drive HDR or DolbyVision, just too less colorrange and values for gradients.
05-08-2018 11:47 AM
Here is the updated INF file: https://pcsupport.lenovo.com/us/en/products/LAPTOPS-AND-NETBOOKS/THINKPAD-X-SERIES-LAPTOPS/THINKPAD-...
For some reasons it's currently only listed for X1 Carbon 6th gen, but I installed it on my X1 Yoga 3rd gen without issue. However, this update only added an ICC color profile for the panel. The color depth info is unchanged.
05-08-2018 12:10 PM
Yes mate, in the URL above. However, here's an extract from the instructions file.
As can be seen, they've made this driver specifically to enable support for Dolby Vision.
CHANGES IN THIS RELEASE Version 220.127.116.11 (N22OI05W) [Important updates] Nothing. [New functions or enhancements] - Added Dolby Vision support. [Problem fixes] Nothing.