JVC RS4500 (native 4K laser projector)

[AVSCraig]

[AVSCraig]

[ARROW-AV]

For the typical film, where is the sweet spot in terms of brightness with a calibrated picture (Ft Lamberts) in a darkened HT environment that most here feel is ideal? Thanks!

I'd say around 16 foot lamberts.

Craig is absolutely bang on as per usual To elaborate, THX professional video calibration guidelines stipulate 14-16fL for projectors displaying HD/2K resolution SDR video, and 30fL for 4K UHD and/or HDR, and 35fL for video display panels including TVs. This is the latest up to date best practice recommendations Where it is perhaps worth mentioning that with respect to DOLBY CINEMAS, which utilize DOLBY VISION projectors, the video image is calibrated to be 30fL    

[ARROW-AV]

Totally agree that adding "infinite" contrast as part of the spec just reduces overall credibility for JVC or any other producer doing the same... The Epson LS10000 hanging in my current cinema just annoys me when shutting off the laser between scenes, does not seem natural at all since the difference between "off" and "on" is such clearly noted...

Very nice to bump into you on here Jon! Just to let you know I will be testing out a JVC RS4500/Z1 on your DREAMSCREEN ULTRAWEAVE V6 screen material next Tuesday... Should make for a good combination me thinks

[AVSCraig]

Very nice to bump into you on here Jon! Just to let you know I will be testing out a JVC RS4500/Z1 on your DREAMSCREEN ULTRAWEAVE V6 screen material next Tuesday... Should make for a good combination me thinks

I'd like to be testing mine out too next Tuesday. No word yet on a ship date. Never has one looked so forward to so big a charge on their credit card. Charge it, send it. Come to Daddy !

[Dylan Seeger]

Craig is absolutely bang on as per usual To elaborate, THX professional video calibration guidelines stipulate 14-16fL for projectors displaying HD/2K resolution SDR video, and 30fL for 4K UHD and/or HDR, and 35fL for video display panels including TVs. This is the latest up to date best practice recommendations Where it is perhaps worth mentioning that with respect to DOLBY CINEMAS, which utilize DOLBY VISION projectors, the video image is calibrated to be 30fL    

Isn't the 100 nit (~30ftL) standard for HDR only for Dolby Vision in commercial cinema? HDR10 on UHD blu-ray is encoded and intended to be played back with at least 1000 nits of peak white brightness for highlights in the image.

With that said, I think it's silly that so many people have arguments over HDR in the consumer world of front projection. Sure, one might look a little better, but they're all compromising accuracy if they can't meet the peak white nit level of the encoded material. Right now I think that all we can hope for is that Dolby Vision on UHD Blu-ray can allow for accurate tone mapping for displays that cannot achieve the appropriate peak nit point of the encoded material. As Kris mentions, nothing right now is tone mapping "accurately". To some people that accuracy matters more than it does for others. I think for the sake of someone like Kris who is trying to objectively compare two HDR projectors that accuracy matters more to say which projector is displaying the HDR content more correctly. But without a way to do that at the moment these comparisons may prove to be difficult and in the end someone like Kris will have to make a judgment call on which projector is doing less harm in that inaccurate tone mapping process with HDR10 content.

Though I'm sure he'll elaborate more on the subject if he wants or correct things if I've made some mistakes on my take of the situation.

[Pultzar]

Kris, are you going to do motion testing to determine the response rate of the projector?  My aging RS1 is not great when it comes to motion handling.

[lygren]

Very nice to bump into you on here Jon! Just to let you know I will be testing out a JVC RS4500/Z1 on your DREAMSCREEN ULTRAWEAVE V6 screen material next Tuesday... Should make for a good combination me thinks

Same config that we will be using here, albeit our showroom has a limit of 13 feet width but I guess that´ll have to do... Also, the UltraWeave V6 will be showcased at the ISE show in Amsterdam come February 7.-10., alongside Alcons Audio and Barco, whileas the "XXL", 3m / almost 10 feet tall fabric is "cooking" as we speak; hopefully I will be able to review the results quite shortly.

Anyhow, back to the Z1, and also the future of projection as such; having seen how a 8,5K Barco 2K was able to light up an 11 feet UltraWeave I do see the need for more light. However, I just installed an RS600 in our 13-feet-width showroom awaiting the Z1 and I have to say; contrast really "allows" for less light! We normally use an RS400 / X5000 in that particular setup, and at a 11 feet wide screen, not the recent upgraded 13 feet, but the RS600 actually - much due to its amazing contrast - lights up the 13 feet with far more confidence than the X5000 / RS400 albeit it only differs slightly in terms of lumens. As such, I really do hope the Z1 boosts contrast levels that exceeds RS400 at least, as the increased light output might not give the result I would hope for if indeed the contrast is not sufficient.

As for the 2K 3-chip DLP Barco @8,5K lumens, the contrast levels are - of course - very low, about 2-4K:1. Still, all that light in combination with Barcos excellent gamma does impress regardless of contrast being that poor, partly due to the ANSI contrast being superior... The question remains if the JVC will impress in the same manner provided contrast does not meet the current "RS"-standards, but I guess time will SHOW!

[AVSMike]

Kris, are you going to do motion testing to determine the response rate of the projector?  My aging RS1 is not great when it comes to motion handling.

JVC has improved on this area, since your RS1, to the point that few complain about motion on the current JVC's. Will be interesting to see if laser allows them to take another step in that direction.

[ARROW-AV]

Isn't the 100 nit (~30ftL) standard for HDR only for Dolby Vision in commercial cinema?

No. It is not only for Dolby Vision in commercial cinema. As stated in my previous post, it is also the THX professional video calibration recommendation with respect to consumer/domestic 4K UHD and HDR projected video images and also display panels, which includes TVs. Where the recommendation with respect to projected image with HD/2K and SDR is 14-16fL, so basically half that

HDR10 on UHD blu-ray is encoded and intended to be played back with at least 1000 nits of peak white brightness for highlights in the image...

Firstly, the 1,000 nits peak is relevant only with respect to video display panels such as TVs, not projectors; and good luck sourcing a home theater projector that can hit 1,000 nits!

Seriously though, you've absolutely hit the nail on the head, or more specifically the root cause with respect to why consumer/domestic HDR is a total mess (and will remain a mess for the next 12-24 months), namely the absence of an agreed grading protocol, and consequently all consumer/domestic HDR video source material has been graded, not with projectors in mind, because the projector subset of the consumer/domestic AV market is a small niche as compared with TVs... So all the focus is on TVs and hence the 1,000 nits peak (540 nits for OLED)... and completely ignoring what is optimum and/or correct for projectors, which is 100 nits / 28fL for HDR and/or 4K UHD video, and where the grading varies to a ludicrous degree from 1,000nits up to circa 8,000 nits and everything in-between... Where this is not going to change anytime soon, so the best course of action is to correct the 'completely-all-over-the-place-grading' via use of an external video processor like the Lumagen Radiance PRO which can be used to remap all video to match whatever is the peak luminosity of your particular HT... Otherwise your video image will not even remotely look its best and will be clipping all over the place etc... Wherein, if you acheive the target of 100nits (=28fL) then you would want to remap all video such that all video fed to the projector is all graded at 100nits (=28fL) just like in Dolby Cinemas

That said, these are GUIDELINES and so it's up to you whether you agree with them and/or choose to follow them... although suffice to say THX doesn't make these recommendations without good reason... And for what it's worth we follow them to the letter 

[ARROW-AV]

Same config that we will be using here, albeit our showroom has a limit of 13 feet width but I guess that´ll have to do... Also, the UltraWeave V6 will be showcased at the ISE show in Amsterdam come February 7.-10., alongside Alcons Audio and Barco...

Well suffice to say I will be gatecrashing your party at the Alcons Audio and Barco booth! And looking forward to meeting you

[Kris Deering]

It will be very interesting to see what the Radiance Pro brings to HDR calibration for projectors. I have one in my rack ready to go once that feature is enabled with the Calman software. It is interesting that THX specifies 30 fL for UHD content. I can see shooting for a peak white of 30 fL with HDR to preserve some headroom but for SDR 4K content that is really bright on a large screen. I tried 30 fL with standard Blu-ray to see what I thought and it was just way too much for my viewing. 16-17 fL seems to be a really great sweet spot in that it looks extremely vibrant and natural without much in the way of fatigue. Some occasional jumps from dark to bright sequences can be aggravating though.

[AVSCraig]

It will be very interesting to see what the Radiance Pro brings to HDR calibration for projectors. I have one in my rack ready to go once that feature is enabled with the Calman software. It is interesting that THX specifies 30 fL for UHD content. I can see shooting for a peak white of 30 fL with HDR to preserve some headroom but for SDR 4K content that is really bright on a large screen. I tried 30 fL with standard Blu-ray to see what I thought and it was just way too much for my viewing. 16-17 fL seems to be a really great sweet spot in that it looks extremely vibrant and natural without much in the way of fatigue. Some occasional jumps from dark to bright sequences can be aggravating though.

30 FL in a dark theater would give my wife another reason to say " turn it down " !

I don't recall seeing you mention what signal sync times are compared with the current RS500 / 600 projectors. Better ?

[thebland]

It will be very interesting to see what the Radiance Pro brings to HDR calibration for projectors. I have one in my rack ready to go once that feature is enabled with the Calman software. It is interesting that THX specifies 30 fL for UHD content. I can see shooting for a peak white of 30 fL with HDR to preserve some headroom but for SDR 4K content that is really bright on a large screen. I tried 30 fL with standard Blu-ray to see what I thought and it was just way too much for my viewing. 16-17 fL seems to be a really great sweet spot in that it looks extremely vibrant and natural without much in the way of fatigue. Some occasional jumps from dark to bright sequences can be aggravating though.

Hi Kris

How much horse power (light output) would a projector need to provide 30ft lambert white peaks for HDR on a larger screen like mine (14' wide 2.40 1.3 gain)?

[AVSMike]

Hi Kris

How much horse power (light output) would a projector need to provide 30ft lambert white peaks for HDR on a larger screen like mine (14' wide 2.40 1.3 gain)?

Not Kris, but the calculation is pretty straight forward. At 1.3 gain, 2,541 lumens. UltraMatte150 microperf is 1.35 gain, so you are looking at 2,447 lumens needed to get 30FL on your screen.