Solving playback issues

[Sewaldo69]

I have an issue where I have horrible images on all dolby vision supported apps while playing DV movies ONLY when I turn on the dolby vision bright setting on my sony a80j tv. When I play the movies on dolby vision dark they're great. The same exact native apps playing the same exact movies through my tv and not using my roku ultra are displaying unbelievably gorgeous images using DV bright. 

I have roku on auto detect,  latest software,  hdmi setting on tv hdmi4 set to enhanced dolby vision, all apps supporting DV, external hdmi set to DV enhanced. 

I bought an ultra 4802x and it did the same thing. I'm sure it's the device because my tv displays them perfectly.  I like the roku interface and want to use it that's why I have an issue. Thanks to anyone who can help. 

[Steverino208]

Check the TV’s Contrast setting under the Picture Quality section.  My Sony 55” A80CJ OLED TV had the contrast settings for the Roku port (HDMI 4) at Maximum, and the OTA TV channels set to 90 (both since lowered to 60).  The picture quality greatly improved after those changes for both inputs.

FYI, I found (as others have also noted) the HDMI cable supplied with the 4802 Roku device apparently does not have the expanded capacity capabilities needed for Dolby Vision support.  

Once I got lowered the Contrast settings, got better HDMI cabling and opened up the HDMI ports on the TV, my Dolby Vision came in great in both Bright and Dark modes.

I didn’t need any changes on the 4802 Roku side…..just let AutoDetect do it’s thing in Display Type.