HDR to SDR in Matrix results in dim image

Apologies if this has been done to death but I couldn’t find a definitive answer.

I prefer sending SDR to my PJ so tried the HDR to SDR setting. Unfortunately the image is a bit dim, lacking pop. I’ve tried both the options “force or BT2020SDR” but they’re the same result. Also played around with the 100 Nits value but that doesn’t seem to do anything.

Is this a known issue with Kodi/OSMC and is anything going on in the background to change it? It’s very obviously not correct.

I can tell my ATV4K to output SDR and then when playing the same 4K HDR files in Infuse they are output correctly in SDR, so it can be done accurately. I would however prefer to use the Vero 4K+ though so I get bitstreamed audio with atmos etc.

Happy to post anything you want, screenshots/logs etc but don’t think there is any issue with my set up. It is just not accurately performing the HDR-SDR conversion.

Thanks for the feedback. Here’s some thoughts.

Have you tried adjusting the contrast in the video settings for each video?

Otherwise, the main difference between the latest (4.9) kernel shipped with Matrix and kernel 3.14 is the HDR-SDR curve is adjusted according to the master display luminance and/or MaxCLL. I would be interested to know if you find things are better/worse depending on those two parameters. Videos with extreme values (such as Mad Max) seem especially difficult to adjust for.

On my (4k) Panasonic LED screen, by default it reduces the backlight when playing SDR and turns it up to max when playing HDR. If I adjust it to max when playing HDR as SDR there is very little difference between the two. I suppose the equivalent on a projector (I don’t own one) is the lamp power or iris setting. Can you check that? Although if you say that’s not a problem with ATV4K, that might not be it.

What is the make and model of your projector, by the way?

Thanks, will have a play, but as you point out it is fine with the ATV4K. Certainly don’t want to have to do that each time.

Projector is a Epson 9400. I tried it on my TV and the same happens on that. Not the end of the world, but would have been ideal to have been able to use the HDR-SDR function.

What would be ideal is after dropping several grand on a projector it would render HDR properly :stuck_out_tongue: What exactly do you find disappointing with the EPSON’s HDR?

Haha. Just not a fan of HDR on PJ’s that much. I can get a suitable image but then have to have high lamp mode which is noisy. Sometimes I will other times I’ll just go with SDR.

I think HDR is far better suited to TV’s

Rather proves my point, doesn’t it? What does SDR with high lamp mode look like? (still doesn’t explain success with ATV.)