Questions About "Dolby Vision VS10 (Output SDR)." It Looks ... Better than HDR?

I'm new to a lot of this so please forgive my ignorance, but I've been trying various output settings and was surprised to see how much better "Dolby Vision VS10 (Output SDR)" looks compared to the HDR options.

I'm using a lower-end laser projector ( LG CineBeam Q, model number HU710PB), so I'm guessing this comes down to the limitations of my own display device which just doesn't have the contrast and brightness to display HDR at its best?

Or is there something special about the way the zx9 pro uses VS10 to convert HDR into SDR?

What am I missing out on by using VS10 instead of HDR?

Does an HDR movie converted into SDR with VS10 look similar to a copy of the same movie that was SDR to begin with? Or does the VS10 version bring something extra to the table?

VS10 into SDR does look a little less colorful compared to the HDR originals. Is that because HDR is using a wider color gamut?

EDIT: I noticed some color changes using VS10 to convert HDR into SDR--particularly, at least on my projector, the color red appears slightly more orange-ish ...

Anyone else with an HDR "capable" display opting for VS10 into SDR because it just looks better on your system?

 

The first thing to say is that the very best HDR that any projector can produce is SDR.

SDR has diffuse white defined at 100nits and HDR at 200nits (used to be 100nits also) and levels beyond that are progressively referred to as specular highlights.

Most projectors struggle to spit out 100nits so you can immediately see the problem.

So something has to tone map as much of the dynamic range as possible and squish it into those 100 ish nits.

That's either down to the projector or the Zidoo (or an outboard processor - MadVR and Lumagen in the main) and in the case of the Zidoo, using VS10, it's rather good at it.

It's not MadVR good, but subjectively, watching real world content, it's not far off.

The only (slight) downside is that in doing so the colour gamut is reduced from Rec.2020 to Rec.709 but most projectors can't get near Rec.2020 anyway.

It would be nice if VS10 could tone map and maintain the gamut at 2020, but unfortunately not.

The other nice thing about VS10 is that if you play Dolby Vision content, the RPU is used in the conversion so you're getting the Dolby Vision dynamic tone mapping as well.

So I'm not surprised at your results at all.

 

I really appreciate your highly detailed and reassuring response. You explained it brilliantly.

My projector can't get very bright--it's only rated at 500 ANSI lumens--but it does have a wide color gamut, including, according to a review from Projector Central, "125.4% of BT.2020," which I assume is above average for RGB laser projectors that cost under a thousand dollars ...

I think the approach that makes the most sense for me is to primarily use VS10 SDR for all the reasons you outlined, and to switch to HDR for material that seems to look better to me in that format. I also discovered that when HDR looks too dark on my projector, I can use the zx9's contrast settings to boost white levels, which for some reason shows a much bigger improvement than adjusting the projector's own contrast settings does.

I initially made the mistake of going with an Nvidia Shield Pro, which is the default recommendation from everyone online when you ask what physical media player you should buy. But I find the Pro to be awful, especially when it comes to directly playing video files off of an SSD. Crashes all the time, freezes, etc. Just terrible. The Zidoo player is like a breath of fresh air in comparison and so much more versatile.

Anyway, thanks again for taking the time to go over this with me.