Considering purchasing the Roku Ultra, but have some questions. If 24p is available for the specific video, will the Roku automatically switch to 24p during playback, and switch back once playback is complete, or is this something I have to manually do in settings each time I want to watch a 24p compatible video? What about HDR? Are there any current platforms (Netflix, Vudu, etc.) that DON'T use HDR10? If so, what happens in that situation? Does the Roku basically just ignore the HDR and you get 4k only?
The Ultra can automatically change frame rates to match what the original fps is of what you are watching if you enable that feature. In my experience it doesn't work that well however. 24fps seems to work ok most of the time but sometimes it is disaster. For instance, I was watching a free movie on Vudu and it changed to 24fps on the Roku. The movie was like it was zoomed in . My TV supports 24, 30 and 60 fps but when the Roku Ultra switches to 30 fps it looks awful. Looks kinda like slow motion and much more jaggedy looking. I turned that feature off and have it display 60 fps all the time.
Vudu has lots of 4k movies that are in dolby vision but not HDR10. When you watch one of those movies you just get 4k. Vudu has recently started having movies with HDR10 but they are nowhere near as plentiful as the dolby vision ones.
4K HDR TV: Samsung UN60KS8000 4K HDR Receiver: Yamaha RX-V381 4K HDR blu ray: Samsung UBD-K8500 4K HDR streamer: Roku Ultra 4640 (2016 model) 4K HDR Gaming: Xbox One X 4K HDR DVR: Directv Genie HS17-500 w/ C61K mini client Cables: Amazon Basics 18Gbps HDMI