Recommended Settings and other useful stuff for RTD 1619DR Players

Hello. I've set the settings you recommend, but I'm getting dark HDR video using Zidoo. Turning on the movie on the TV with Vimu Media Player I get a brighter image. What do I need to change in Zidoo settings? Unfortunately, the photo could not convey the differences. But on Zidoo I see a very dark image with no glare of light on the skin. All that is shown in the photo is the features of the phone's camera.
Zidoo settings




TV

 

@Markswift2003 about JVC projector with HDR support (RS420 here), it's better to push the lamp to the max power for best experience? I mean, with the gamma curve I found in the PDF you attached in post #1, I know that the JVC will not switch to HDR mode but the goal is the same as HDR so lumen as much as we can?

Thanks!

 

No, no need at all - it's personal preference of course but it's a very common misconception that HDR means a "brighter" image.

It absolutely shouldn't, and in fact for a correctly mastered HDR image, the APL (Average Picture Level) should remain roughly consistent between an SDR and HDR grade with only contrast range increasing and any overall brightness only attributable to specular highlights.



It should also be borne in mind that the difference between say 200nits (diffuse white) and 1000nits is logarithmic so it's nothing like 10x brighter as most people think.

Bottom line, a projector may output say 70-100nits max and the difference between low and high lamp doesn't really make a huge difference - yes you'll scrape a couple more nits out of it, but you also increase black level, increase fan noise and reduce lamp life at the same time so I don't think the trade off is worth it. Personally I always run in low lamp.

 

First thing I'd do is check black level (brightness) of the TV using a black clip pattern:

https://www.avsforum.com/threads/hdr10-test-patterns-set.2943380/

Black should be at 64 so anything below that should not be visible and anything above should be.

 

Thanks mate.
So if it's a best practice to achieve about 45-50nits in SDR, 70nits is already a good target for LLDV and your gamma curve, right? I'm exactly in the condition you said: 70nits low lamp open iris, 100nit high lamp open iris.

 

Not sure where the 45-50nits comes from - the output of the projector is the output of the projector and if your projector does 70nits, that's measured at peak white in SDR so that's your target - although as I say, it's not really a target, it just is what it is.

But if you're happy with the SDR picture on low lamp then leave on low lamp for LLDV, it should be plenty and as I say, by all means try high lamp out of curiosity - my experience is that it doesn't make enough difference to make sense using it.

 

Hi Mark, just wondering if you've had any feedback from Zidoo about this yet and whether its fixable.

 

Other than I know that the devs have been informed, sorry no.

 

OK thanks. Just checked my LG TV internal player and it shows all the gradations. It is quite a big problem because any dark films in DV like Harry Potter and Star Wars show black blobs that look like low bitrate encoding rather than smooth gradation.

 

So, when I'm using my Roku Ultra to watch Netflix, Disney+, Prime, etc, I can go from the UI to a movie almost instantaneously with no HDMI re-handshaking. On the UHD3000, Going from the Posterwall to playing a movie often results in a long 10+ second blackout and re-handshake between the Zidoo and my JVC projector. I've locked the GUI to 3840x2160/23. Most of my movies are also in 3840x2160/23. So even though I have "Match Resolution and framerate" selected, neither the resolution nor framerate is changing. Why does the HDMI drop out? Is there any way to fix this? It definitely takes away from the otherwise excellent Posterwall experience.

 

Probably changing from SDR to HDR.

 

HDMI will send a resync signal on either a change of resolution, framerate, HDR or Gamut so the way to mitigate HDMI resync is to set the GUI the the same resolution, framerate and HDR/Colour Gamut of the majority of your content.

JVC projectors have quite possibly the worst HDMI resync time in any display ever! My X7000 (RS500) takes approx. 15s to resync - it's infuriating.

The way I used to get around it before VS10 was to use "Mapping HDR10" but these days I send everything as BT.2020 LLDV to the JVC. I set resolution and framerate to 4K23 and set Frame Rate Mode to Frame Rate only so the only time I ever see a resync is when the framerate isn't 23.976 which is quite rare.

Presumably you're using HDR > Auto and therefore in your case, if resolution/framerate isn't changing and the GUI is in SDR Rec.709 you'll see an HDMI sync when you play HDR BT.2020 content because both the HDR mode and the Gamut is changing.

 

Yeah, that's an easier way of saying it

 

So here's the complication. I don't want the Zidoo to upscale 1080 content, nor do I want it to handle HDR tone mapping. I have a MadVR Envy that I want to handle all scaling and HDR. Any possible workaround?

 

I'll ask the same question. Would a Vertex2 allow me to eliminate the SDR-HDR hiccups switching from Posterwall to content and vice versa?

 

No - you have to work out a scheme whereby neither resolution, framerate, HDR mode or colour gamut changes or at least minimise it.

As I say, if one of those changes, the HDMI resyncs, and that's not down to the Zidoo, it'd down to the display.

Surely the Envy can output everything in one mode with the exception of frame rate? I set the GUI to 4K23 LLDV and everything is output at 4K LLDV so I have very minimal resyncs - can't the Envy do the same? (I know it can't handle Dolby Vision, but can't it output everything in a specific HDR mode/Resolution?)

 

The Envy is set to always output 4096x2160 (native res for NX5). The frame rate is variable since a lot of streaming content (Netflix) is 59.94 and all my MKVs are 23.97. HDR is kind of variable too. The Envy is always mapping to SDR BT2020 but is passing an HRD flag to the JVC projector in order to work properly with SDR Rec 709 content.

The net effect of the current setup is that everything looks stunning. SDR, HDR, 1080, 4K all look amazing. It’s also why I want the Envy handling all the video processing tasks.

The weird thing is that even though the Roku GUI is in SDR, when playing HDR content, there is no re-handshaking like on the Zidoo. What’s different here.

 

It is possible, although not good practice, to change HDR modes without resyncing HDMI, so I guess the Roku does that. The Shield does the same.

So if the Envy is tone mapping HDR 2020 to SDR 2020 can you not let it map SDR 709 to SDR 2020 as well?

 

@Markswift2003 is there any chance you could check the bias lighting test pattern with a 10,000 nits DV EDID block and see what happens?