May 23
DBLE Artefacts - Limited Range and Gamma
YouTube Test Video: https://youtu.be/AYtvehF9-Z8?si=78_trMH2KPBlGZ4TReproduction Steps1) Ensure your source device is outputting in limited range2) Ensure projector range is set to Auto.3) Reset all image settings (may not be necessary, but ensures we are on equal footing)4) Set Iris to a fixed level to rule out dynamic iris causing pumping.5) Enable DBLE6) Test the YouTube video linked above with gamma set to 2.2, 2.3 and 2.4 and notice how different the results are.7) Set your source device to output in full range.8) Test again with gamma set to 2.2, 2.3 and 2.4 and notice how things look the same at each level.With limited range and DBLE enabled, you should be able to observe something like the below.Gamma 2.2Square stays white. Some small flickering. DBLE not really dimming very much at all.Gamma 2.3Massive flickering and swings in black floor. 12 seconds is the first big flicker, but there are smaller ones before that.Gamma 2.4Dims to a pink square at 12 seconds and then stays fully dimmed, no flickering, square is pink at all timesThis bug potentially has far reaching consequences for black and white crush if the gamma is pushing black below 16 and white above 235.
Pending
Hi I have captured a video of a potentially related issue that is 100% reproducible on an Apple TV HDR 2015. The short story is that setting the Apple TV to YcBcR HDMI Output causes the small white square to shift to magenta, whereas selecting either RGB High or RGB Low the box stays white. My video of the problem is here: https://youtu.be/i6ZU5_6daCg?si=eCSVOpm2xoeKaxb5 I do misspeak a few times in the video and say "Full" istead of "Auto" when switching the projectors HDMI Range. The black fluctuations when changing between Limited and Full are also not visible in the video. Apologies. I believe this could well be related to the initial issue I reported on the Shield TV Pro 2019 here. YouTube Test Video: https://youtu.be/AYtvehF9-Z8?si=78_trMH2KPBlGZ4T