I'm trying to figure out which is better and why. I've been search for this for the last couple of days. Most people seems to prefer DTM+LLDV but I don't quite understand the logic. DV profile 7 is HDR10 base layer plus DV dynamic metadata which LLDV engine uses to do dynamic tone mapping on a scene by scene base. DTM+HDR10 is doing dynamic tone mapping with HDR10 base layer on a frame by frame base. So DTM+HDR10 should be better than LLDV right? Then comes the DTM+LLDV mode. I don't know who is doing dynamic tone mapping with this combination. Some scenes by DTM on a frame by frame base and others by LLDV engine on a scene by scene base? why is this mode better than the other two? Am I getting something wrong?
* If you're using Z9X Pro as shown in the signature, you are in a wrong thread. * If you're using Z9X 8K, try Auto first and then workaround with the several EDIDs provided with the box. Finally @Markswift2003 can help you with a specific EDID for your JVC PJ.
Dolby Vision isn't just about tone mapping - depending on the Content Management version used in post, there are trims to control Lift, Gain and Gamma for example and the colourist can tune the image on a frame by frame basis if they wish. So there's often a subtle difference between the HDR10 layer and the Dolby Vision layer which also depends on the EDID settings (ie the display). If you're interested, there's more info here: The Dolby Vision Trim Controls There's no right or wrong here - you kind of have to suck it and see - I used to find that setting T_MaxPQ in the Dolby Block to 400nits was optimal for my old projector (without DTM) so that the Dolby algo tone mapped (and trimmed etc) above 400nits and the static custom gamma curve in the PJ took it the rest of the way. On my new PJ with DTM, I find that setting T_MaxPQ to 1000nits seems to to do a better job - in this instance the Dolby algo is doing very little below 1000nits, but on the odd occasion that you get something above that it kicks in and DTM takes care of business below. That's the theory, but I also find the Dolby Vision image to be more pleasing than the HDR10 layer and at the end of the day that's what it's all about. Bottom line, give it a go. If you like it, use it, if you don't, don't.
Thank you for the explanation, Mark. So with new JVC DTM what you get from profile 7 DV is basically HDR10 + DV trims and stuffs + DTM all combined right? By the way, I'm glad you are back. Could you help check my edid I posted on the EDID thread? I'll give it a go.
Yes exactly - if you reduce T_MaxPQ below 1000nits you start to hand off the tone mapping to the VS10 engine rather than using DTM and since the JVC DTM is pretty good, I find 1000nits to be kind of the sweet spot. Attached is your AVR EDID with Dolby blocks added for 1000nits and 4000nits. Also if you want to try a range, there's a zip file with EDIDs from 100 to 10,000nits. These are generic so do not include HDR10+ but I would avoid that on JVC projectors anyway because it knobbles a bunch of settings and HDR10+ isn't exactly great anyway! Out of interest, which JVC is it?
HDR10+ is very limited in comparison to Dolby Vision and on JVCs it's badly implemented too - a lot of picture settings are greyed out and locked - Kris Dearing on AVS went into this in some detail but I have no idea where or which thread it was... Long tall and short of it is it's best avoided.
I did some tests with a couple of movies. It seems to my eyes that LLDV+DTM with 1000nits EDID is pretty much the same as the HDR10+DTM, but with 4000nits EDID, LLDV+DTM is noticeably brighter. Could someone explain why? Thanks.
With a 4000nit EDID what you're essentially saying to the player is that the display is capable of displaying up to 4000nits so you don't need to do any tone mapping at all so the PJs DTM is doing all the heavy lifting. Why it's "brighter" will probably be down to the JVC's algo and setup. It's up to you what level you use as to what looks better - personally I go for a more subdued cinematic look and I find having the laser set too high is simply too bright, so I knock it back a bit. But everyone's taste is different and the bottom line is if it looks right, it is right (up to a point!).
