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Panasonic UB900

AVSCraig

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Re: Panasonic UB900
« Reply #15 on: December 21, 2016, 04:49:32 PM »
The dynamic range slider is best left alone unless you dont mind messing up the white clipping point, it works pretty much like the contrast adjustment on most displays.. The SDR output will alow you to display a HDR movie on a display capable of 200nit/ 60fl or more, and look like it was intendet from 0 to around 70% IRE.

So for maximum image fedelity HD blu ray is still the only thing that will work right on a projector, the UHD HDR needs pile of compromises to get a decent result on a low light display.

Try measure the SMPTE 2084 gamma curve on your projector at different HDR converter settings, using UHD HDR patterns.

The slider is best left alone. But so far, 4K UHD BR's watched with HDR convered to SDR BT2020 looks better than standard Blu Ray. No question. HDR - not so much.
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Re: Panasonic UB900
« Reply #16 on: December 22, 2016, 12:54:01 AM »
The slider is best left alone. But so far, 4K UHD BR's watched with HDR convered to SDR BT2020 looks better than standard Blu Ray. No question. HDR - not so much.

Whats your max light output calibrated.? And how do your colors track BT2020.?
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Re: Panasonic UB900
« Reply #17 on: December 22, 2016, 09:18:24 AM »
Not sure why max output is relevant. On the JVC RS600, the problem with HDR is that it disables the auto iris and raises black levels to a point that the blacks look grey. The excellent contrast of these projectors is their best feature. HDR doesn't bring enough to the table to offset the compromised black levels. it's pretty easy to see flipping back and forth with a Blu Ray.

I don't think HDR really works on any projector, other than a Digital Projection light cannon ( and they don't have very good black levels to begin with ). 
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Re: Panasonic UB900
« Reply #18 on: December 22, 2016, 11:06:40 AM »
Not sure why max output is relevant. On the JVC RS600, the problem with HDR is that it disables the auto iris and raises black levels to a point that the blacks look grey. The excellent contrast of these projectors is their best feature. HDR doesn't bring enough to the table to offset the compromised black levels. it's pretty easy to see flipping back and forth with a Blu Ray.

I don't think HDR really works on any projector, other than a Digital Projection light cannon ( and they don't have very good black levels to begin with ).

The max lightoutput is very relevant as the movie is mastered in SMPTE 2084, and thats a static HDR, and the SDR output you still need to follow the SMPTE 2084 up to around 60-70% IRE before the HDR converter compresses the highlight area. The SDR is not SDR like we normaly use it, thats why the image looks terribly dim and lifeless if you run it with 20fl on the screen, you need around 60fl to do the UHD SDR output, and track the 0-70% IRE.. So as long as we are working with a HDR format as it is today, its very very relevant how much light you can dump on the screen, and to give a bit of meaning to the format we have to have more light to create a bigger dynamic range.

If you use the HDR convertion adjustment like on the UB900 you move the white clipping point, wich is never a good idea.
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Re: Panasonic UB900
« Reply #19 on: December 22, 2016, 11:40:41 AM »
The max lightoutput is very relevant as the movie is mastered in SMPTE 2084, and thats a static HDR, and the SDR output you still need to follow the SMPTE 2084 up to around 60-70% IRE before the HDR converter compresses the highlight area. The SDR is not SDR like we normaly use it, thats why the image looks terribly dim and lifeless if you run it with 20fl on the screen, you need around 60fl to do the UHD SDR output, and track the 0-70% IRE.. So as long as we are working with a HDR format as it is today, its very very relevant how much light you can dump on the screen, and to give a bit of meaning to the format we have to have more light to create a bigger dynamic range.

If you use the HDR convertion adjustment like on the UB900 you move the white clipping point, wich is never a good idea.

It's actually not dim at all, but I do prefer to watch standard blu Rays around 18 foot lamberts. I have flipped back and forth from Blu Ray to 4K Blu Ray, and brightness wise, with both my RS600 and VW600, there is no difference ( using the HDR to SDR BT2020 conversion ). I do need to open the manual iris from -7 to -5 or -4 on my JVC, when watching 4K Blu Rays.  Most of my 4K UHD Blu Rays are mastered at 1000 nits I believe ( I need to re-visit the website that has that info ).   

I'm leaving the HDR conversion adjustment alone, but I was just interested to see how it worked.
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Re: Panasonic UB900
« Reply #20 on: December 22, 2016, 01:37:59 PM »
I asked another RS600 owner how much light he got on screen, and he told me 46fl, dont know what screen size he is running, but il think that would make it work pretty well for the UHD SDR.
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Re: Panasonic UB900
« Reply #21 on: December 22, 2016, 02:28:35 PM »
I asked another RS600 owner how much light he got on screen, and he told me 46fl, dont know what screen size he is running, but il think that would make it work pretty well for the UHD SDR.

The highest I measured on my screen was 44 foot lamberts. But who wants to watch in high lamp with the iris wide open? That negates the very best attribute of the JVC projector - contrast and black levels. Watching in HDR on many movies produces a picture that looks inferior to the Blu Ray ( due to gray blacks ). Converting HDR to SDR with the wide color gamut produces a visibly better picture with 4K Blu Rays.  And it certainly doesn't need to be more than 16 or 18 foot lamberts.
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Re: Panasonic UB900
« Reply #22 on: December 22, 2016, 04:06:47 PM »
The highest I measured on my screen was 44 foot lamberts. But who wants to watch in high lamp with the iris wide open? That negates the very best attribute of the JVC projector - contrast and black levels. Watching in HDR on many movies produces a picture that looks inferior to the Blu Ray ( due to gray blacks ). Converting HDR to SDR with the wide color gamut produces a visibly better picture with 4K Blu Rays.  And it certainly doesn't need to be more than 16 or 18 foot lamberts.

I agree about the contrast and black level.. But not that 16 or 18fl works for UHD SDR..  It runs a way to high gamma out of black, making the image way more dim than a normal HD movie, unless you fiddle with the contrast or HDR converter, and add a serious amount of white clipping, or have a processor to change the shape of the gamma.
The SDR output you get from the UB900 is not SDR, its a HDR with a brakpoint/ gamma roleoff to compress the highlights.. Its still mastered for 1000nit or more, and you compress that to 55-60nit.

Sure we can like or dislike whatever we want, having a subjective opinion about it, but objectively, its a mess.

The ilustration is a 30fl UHD SDR curve. it looks a bit like a 8-10fl HD image to me, as i see it its not that we need the huge amount of light output in the average movie content, so might work if the roleoff on the highlight was steaper, like the converter adjusted the 65% ire point up and down holding black and white reference, but it dont.

What gamma do you run on your HD calibration.?

« Last Edit: December 22, 2016, 04:15:08 PM by stridsvognen »
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Re: Panasonic UB900
« Reply #23 on: December 22, 2016, 04:55:21 PM »
I agree about the contrast and black level.. But not that 16 or 18fl works for UHD SDR..  It runs a way to high gamma out of black, making the image way more dim than a normal HD movie, unless you fiddle with the contrast or HDR converter, and add a serious amount of white clipping, or have a processor to change the shape of the gamma.
The SDR output you get from the UB900 is not SDR, its a HDR with a brakpoint/ gamma roleoff to compress the highlights.. Its still mastered for 1000nit or more, and you compress that to 55-60nit.

Sure we can like or dislike whatever we want, having a subjective opinion about it, but objectively, its a mess.

The ilustration is a 30fl UHD SDR curve. it looks a bit like a 8-10fl HD image to me, as i see it its not that we need the huge amount of light output in the average movie content, so might work if the roleoff on the highlight was steaper, like the converter adjusted the 65% ire point up and down holding black and white reference, but it dont.

What gamma do you run on your HD calibration.?


I've been using a gamma of 2.4.  I agree, it's going to take some time for 4K UHD calibration discs etc. to bring everything back under control. In the mean time, it's not a bad ( subjectively ) looking picture. And most of my watching is ( and will be ) HD sources for quite some time. It's just fun to play with this new 4K UHD stuff in the mean time.  :)   
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Re: Panasonic UB900
« Reply #24 on: December 27, 2016, 10:49:07 AM »
Watched " The Shallows " last night. Sure a bright picture without HDR. The 4K disc looks pretty darn good. Then I tried out a few apps built in. Going to stream a triathlon movie tonight my wife has been wanting to see from Amazon ( not in 4K ). It's handy having short cuts on the remote such as " internet " to jump to other sources. So far, I like this player.
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Re: Panasonic UB900
« Reply #25 on: May 03, 2017, 09:08:27 AM »
Watched " Allied " on 4K UHD Blu-ray last night with my wife. She enjoyed it. I must say that with the new dynamic range slider, 4K Blu-rays now look really good - the problem of them being too dark is a thing of the past. 
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