DP 1.2 to HDMI 2.0 - colours are off

[iBSOD]

Hi there,

I have a R9 390 gpu, and a 4k tv. I use a Club3D active adaptor to get 4K@60hz.

I've had this setup for a while, and noticed the colours seemed a bit dark but never thought much of it until today. I was watching a video on the 4k tv via my PC, and the scene was way too dark to discern anything. I switched output to my PC monitor (XG270HU) and all the detail in the scene was apparent. I then played the same video file on the 4k TV via the smart functionality, and the detail in dark scenes were apparent.

So, it seems that some setting may be wrong PC-side, though I'm not really sure what to look for. Could this be a limitation of the adaptors capabilities? (IE regarding chroma sub-sampling limitations?)

Thanks

 

[Rroff]

Somewhere or other limited range RGB is in effect - it might be the colour format supported by the adapter I dunno I remember there was some comments about that but not sure what the details were. Sometime there is an option for that in the driver control panel or the display's OSD.

 

[iBSOD]

Somewhere or other limited range RGB is in effect - it might be the colour format supported by the adapter I dunno I remember there was some comments about that but not sure what the details were. Sometime there is an option for that in the driver control panel or the display's OSD.

Yeah that does does sound about right. Cant seem to find any RGB range settings tho, in Catalyst and Windows. I remember something similar with NVidia when I had GTX 465, had to manually set RGB range to full

 

[gareth170]

the adapter supports 4:4:4 for 4k@60hz,

does your tv have computer/pc mode?

I'm asking because my 4k tv has 2 modes, gaming and computer mode modes, when i select gaming mode the picture looks dark, but in computer mode the picture looks as it should.

 

[iBSOD]

the adapter supports 4:4:4 for 4k@60hz,

does your tv have computer/pc mode?

I'm asking because my 4k tv has 2 modes, gaming and computer mode modes, when i select gaming mode the picture looks dark, but in computer mode the picture looks as it should.

Its a Philips tv too so yeah. I have remedied the problem atm by increasing brightness a small amount in Windows, which seems to bring back some detail at the expense of lighter scenes. I've decided to upgrade to a GTX1070/1080 now tho

 

[David Bisset]

Sounds exactly like the TV taking it as limited range - I'd be checking TV settings rather than anything on the computer as a first step.

Edit: Think I'm confusing myself. I guess it depends are dark bits darker than expected, or light bits darker than expected, or is there 'black crush'? Urgh. Anyway both TV & GPU need to agree on format though I'd expect going via DP from the card it'd default to full RGB?

 

[VincentHanna]

You still have to set it to full RGB mode in the AMD card.

I haven't used AMD cards for 18 months or so, so can't remember exactly where it was.