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The throw distance is actually 14.5' and works fine with my present Sony 300ES
Yes, all four should work at 14'-6", but not at the 14' that you asked. The Sony projectors are really close, listing 14'-5". The RS2000 14'-1" and the RS3000 13'-8". With you size screen you can do low lamp with the JVC, the 915 of course can be dialed back. The 715 may be on the dim side in low lamp, since low on it is less lumens than the JVC 2000.

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With your size screen, if I was using the RS2000, I would run on high and use the DCI filter. Might click the manual iris closed a couple clicks to pick up some contrast. With the 715, I would also use high. With movie playing, noise level does not bother me and my projector is close to my head.
 

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I dont understand this. You always have the possibility of an infinite dynamic range in the signal. Black is coded as zero, so any value divided by 0 is infinite. What about an ansi checkerbord pattern? It will look identical no matter if you code it as HDR or SDR.
You don't understand why the industry came up with and standardized on the hdr spec using SMPTE ST 2084 instead of continuing to use BT 1886 (gamma) for high dynamic range images?
 

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I am disappointed to read in the PassionHomeCinema review of the Sony 590 that he found the operating noise to be an issue. Do the Sony 590(715) and JVC NX7 need to be on high lamp to achieve good HDR, and which unit is loader in both low and high lamp modes?
am running low lamp but also run a relatively smaller screen though longer throw..

its something we may know about more with the upcoming update... how will htoptimiser work with larger screens will you be able to run on high setting and still get a pretty decent result ? without needing to be on high lamp ?
 

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Yes, all four should work at 14'-6", but not at the 14' that you asked. The Sony projectors are really close, listing 14'-5". The RS2000 14'-1" and the RS3000 13'-8". With you size screen you can do low lamp with the JVC, the 915 of course can be dialed back. The 715 may be on the dim side in low lamp, since low on it is less lumens than the JVC 2000.

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With your size screen, if I was using the RS2000, I would run on high and use the DCI filter. Might click the manual iris closed a couple clicks to pick up some contrast. With the 715, I would also use high. With movie playing, noise level does not bother me and my projector is close to my head.
Thanks. Forgot that 1/2 a foot can make a big difference. My pj is also over my head (bad instal choice), and the fan on high is noticeable. Doubt I'll spring for a 915ES but understand it is quitter than the lamp based pj's.
 

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Thanks. Forgot that 1/2 a foot can make a big difference. My pj is also over my head (bad instal choice), and the fan on high is noticeable. Doubt I'll spring for a 915ES but understand it is quitter than the lamp based pj's.
At 100% is is pretty loud, but back it off to 80% and it is not very loud.
 

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am running low lamp but also run a relatively smaller screen though longer throw..

its something we may know about more with the upcoming update... how will htoptimiser work with larger screens will you be able to run on high setting and still get a pretty decent result ? without needing to be on high lamp ?
Sorry, what are you referring to with "...how will htoptimiser work..."
 

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Well that doesn't sound like its "...not very loud", at least not worth the extra $ for noise fan alone:(
I guess it depends how much it bothers you. I run high lamp for HDR on my projector and think nothing of it, because the movie is louder than the fan. Yes, if I listen for it in quiet scenes, I can hear it, but usually I am paying attention to the movie and never notice.
 

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I guess it depends how much it bothers you. I run high lamp for HDR on my projector and think nothing of it, because the movie is louder than the fan. Yes, if I listen for it in quiet scenes, I can hear it, but usually I am paying attention to the movie and never notice.
I have the same with my present set up, but was hoping my next pj would resolve this first world problem :D . Well I'm glad the laser 915 is not so quit that I would be tempted to make the leap.
 

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I guess it depends how much it bothers you. I run high lamp for HDR on my projector and think nothing of it, because the movie is louder than the fan. Yes, if I listen for it in quiet scenes, I can hear it, but usually I am paying attention to the movie and never notice.
I think fan noise only bothers some the first month you purchase a new projector. I can run my 640 on high and not think anything of it.. The movie im watching is ways louder than the fan.

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You don't understand why the industry came up with and standardized on the hdr spec using SMPTE ST 2084 instead of continuing to use BT 1886 (gamma) for high dynamic range images?
No, I don't understand the claim that "SDR gamma is not capable of storing / representing truly high dynamic range scenes. For example, a highlight that's 1000, or even more times brighter than another element in the scene ".

The way I understand it (which is probably incomplete but I expect not completely off the mark): SDR gamma can easily represent a highlight that is 1000 times brighter than another element. Otherwise you couldn't have more than 1000:1 in contrast. There is in fact no limit to the dynamic range in SDR. The problem with it is that in HDR the normal dynamic range (excluding highlights) that includes most of the image information (the SDR part of the image) is squeezed down to 1-10% of the total range of the signal (1000-10,000 nits HDR). That means you only have 1-10% dynamic range left for encoding the SDR part of the image, which I imagine could lead to severe banding and other artifacts (squezing the SDR range down to 1-10% would imply a decrease in bit depth by 3-7 bits). Especially in darker scenes where you might only use 2% or so of the overall range of SDR. Divide that with another factor of 10-100 to save overhead range dedicated for highlights and you can see we are getting into trouble...
 

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No, I don't understand the claim that "SDR gamma is not capable of storing / representing truly high dynamic range scenes. For example, a highlight that's 1000, or even more times brighter than another element in the scene ".

The way I understand it (which is probably incomplete but I expect not completely off the mark): SDR gamma can easily represent a highlight that is 1000 times brighter than another element. Otherwise you couldn't have more than 1000:1 in contrast. There is in fact no limit to the dynamic range in SDR. The problem with it is that in HDR the normal dynamic range (excluding highlights) that includes most of the image information (the SDR part of the image) is squeezed down to 1-10% of the total range of the signal (1000-10,000 nits HDR). That means you only have 1-10% dynamic range left for encoding the SDR part of the image, which I imagine could lead to severe banding and other artifacts (squezing the SDR range down to 1-10% would imply a decrease in bit depth by 3-7 bits). Especially in darker scenes where you might only use 2% or so of the overall range of SDR. Divide that with another factor of 10-100 to save overhead range dedicated for highlights and you can see we are getting into trouble...
In HDR, 0-100 nits is the first 50% of the whole range, 100 to 10,000 nits its 50-100% of the rest of the signal.

But overall I think you are close yes.

As for gradations, well, 10bit is 10bit weather its SDR or HDR, you still have the exact same amount of gradation available in the signal path. As such I dont see a problem with DTM using an SDR Gamma container to encode the signal.

There is actually still an EOTF style manipulation going on with that gamma the whole time! See here, I can induce it myself from the raw HDR video feed and make it look almost identical to the DTM Tone Mapped image, how do I do that? I put an S Curve on the image almost exactly like the BT2390 style curves we used in the Arve Tool on the JVC, which was still a PQ curve at the end of the day (NOT SDR container).


Raw image



Note the curve, Looks familiar to those who have spent time making custom curves..



DTM version, slight saturation difference, essentially nothing to do with the S Curve though.

 

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In HDR, 0-100 nits is the first 50% of the whole range, 100 to 10,000 nits its 50-100% of the rest of the signal.

As for gradations, well, 10bit is 10bit weather its SDR or HDR, you still have the exact same amount of gradation available in the signal path. As such I dont see a problem with DTM using an SDR Gamma container to encode the signal.
In HDR yes, but if you put that signal to SDR straight gamma without compressing the range then 0-100 nits would only be 0-1 % of the whole 10 000 nits signal. That would probably lead to gradation problems.

HDR signal tonemapped to 0-200 nits or 0-400 nits I can't see a problem there! But maybe with a 1000 nits display maybe the SDR range 0-10% can get a little crowded?
 

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In HDR yes, but if you put that signal to SDR straight gamma without tonemapping then 0-100 nits would only be 0-1 % of the whole 10 000 nits signal. That would probably lead to gradation problems.

HDR signal tonemapped to 0-200 nits or 0-400 nits I can't see a problem there!
But that's not what is happening, and I don't think that's the point being discussed. Dynamic tone mapping outputs a fresh optimised 0-100% range for every frame up to measured frame peak. It's still bt2390 in appearance. It's not linear all the way to 10,000 nits just like HDR isnt, look to my curve for a clue, the image above is technically still an SDR gamma yet the image looks right, that's because I added a curve on it which replicates somewhat a bt2390 curve, if you look at the curve we are compressing highlights and the 0-100nit range is quite wide.
 

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But that's not what is happening, and I don't think that's the point being discussed. Dynamic tone mapping outputs a fresh optimised 0-100% range for every frame up to measured frame peak. It's still bt2390 in appearance. It's not linear all the way to 10,000 nits just like HDR isnt, look to my curve for a clue, the image above is technically still an SDR gamma yet the image looks right, that's because I added a curve on it which replicates somewhat a bt2390 curve, if you look at the curve we are compressing highlights and the 0-100nit range is quite wide.
I know it's not a problem with tonemapping to low nit displays. But I was thinking that with real high nit displays(10 000 nit) the standard gamma could not be used because too small part of the signal would be left for the 0-100 "normal" picture range and that is part of why HDR was invented. Of course there are other positives like the absolute brightness values in the hdr signal, but that is handled correctly when the tonemapping system knows the actual brightness of the display the signal is being tonemapped for.
 

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I know it's not a problem with tonemapping to low nit displays. But I was thinking that with real high nit displays(10 000 nit) the standard gamma could not be used because too small part of the signal would be left for the 0-100 "normal" picture range and that is part of why HDR was invented. Of course there are other positives like the absolute brightness values in the hdr signal, but that is handled correctly when the tonemapping system knows the actual brightness of the display the signal is being tonemapped for.
Sure but I thought we were talking about how if we use DTM then it cannot be considered HDR.

Clearly not the case. Even if you told DTM you had 10,000 nits it would still not be linear like you think it might. The specification doesn't dictate that, so putting it inside an SDR container won't do that either.

If you want to see what linear looks like, open an HDR film but put your display into SDR mode, it will be very washed out, the image is just not designed to look like that, what is also still clear is the 0-100nit range of the image is very much still visibly half the signal bandwidth.
 

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Sure but I thought we were talking about how if we use DTM then it cannot be considered HDR.

Clearly not the case.
I agree. (And yes, this is a sidetrack but interesting!)
Even if you told DTM you had 10,000 nits it would still not be linear like you think it might. The specification doesn't dictate that, so putting it inside an SDR container won't do that either..
This I disagree. Isn't tonemapped "SDR container" signal linear though? I mean you are or should be using a straight gamma in projector so it has to be linear. And for that reason maybe there is a limit with display brightness where "tonemapped hdr in sdr container" cant be used anymore.
If you want to see what linear looks like, open an HDR film but put your display into SDR mode, it will be very washed out, the image is just not designed to look like that, what is also still clear is the 0-100nit range of the image is very much still visibly half the signal bandwidth.
Thats a different situation. That is coded as a HDR. I was talking about a HDR signal "tonemapped" to a SDR gamma for a 10 000 nits display. Imo it has to be linear. With 100 nits projector it would look super dim, but with a 10 000 nits display it would look right.
 
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