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Well I get the same posterization issues if I for example try to make a P3 3DLUT for my JVC NX5 even though it's like 94% coverage.

I also saw it pretty bad when I made a rec709 3DLUT on a friends NX7 when I was making it over a stock calibration which was only 89% rec709 coverage (before autocal).

I am not saying it's because of not reaching the full gamut, but I just don't know what causes it to be honest.

I can make a P3 3DLUT for my LCD PC monitor which is only 78% coverage (it's not even meant for P3 or HDR) and there are no posterization artifacts.

So I really don't know what causes it, but I have seen it often on various projector 3DLUTs.

I wont say that every projector has it, but so far most that I have tried seem to. The only time I haven't seen it on a projector was when the projector could reach or exceed the target gamut. So I feel gamut coverage is somehow tied in there, though it's definitely not the entire story by any means.
Same here, i do get some posterization with my jvc rs440 when i do a p3 3dlut since it covers 92% p3, with the lk970 i get worse posterization for rec709 3dlut. But with the M150 i dont get any at all when i do bt2020 3dlut while it covers around 90%, i guess there is other factors to it, maybe color luminance .
In Lightspace there is a color gradient test image that shows all the artifacts pretty clearly if theres any after the 3dlut, and its extremely smooth and artifact free with the m150.
U may be right that no content probably get over 90% bt2020 to show any error any way but if that is the case why does ur monitor doesnt show any.
 
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Out of curiosity... how difficult would it be to stack two q750i projectors? Perhaps side-by-side, or above/below a shelf? Anybody have ideas for this? It would have to be perfect, otherwise I'd be throwing away the sharpness and defeating the point.
 

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Discussion Starter #1,703
Out of curiosity... how difficult would it be to stack two q750i projectors? Perhaps side-by-side, or above/below a shelf? Anybody have ideas for this? It would have to be perfect, otherwise I'd be throwing away the sharpness and defeating the point.
runco made one

i dont know that there's enough lens shift for side by side so you would need blending software or something like that. Zombie vertical stacks 2 sharp projectors with no rig so it could be fairly simple.
 

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Discussion Starter #1,704
@Dennis Moore had you gotten the 3dlut and dtm working? what was your screen size/material?
 

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Discussion Starter #1,706 (Edited)
Haven't had time to play with it lately... maybe this weekend. The screen is about 100", the material is DIY painted, Silver Fire 4.0.
do you use SatCo or Adaptive Contrast? I think you said you were noticing some color shift using constant contrast? You said you have the gamut set to native and not pce right? And were you set to madvr-limited, nvidia-rgbfull, runco-rgbvideo?

When you redo the 3dlut, maybe reinstall displaycal and go into windows color management and ensure any previous profiles arent loaded. Then make sure you dont do that 1dlut.

How did you have the meter positioned before? The 1dlut might have been the only issue but im curious, as with that paint there may be reduced offaxis gain so if the meter is lower than the center of the screen and pointed up towards the center it can skew the measurement.

Do you find light output adequate with SDR material? What are your contrast/brightness/gamma settings?
 

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i dont know that there's enough lens shift for side by side so you would need blending software or something like that. Zombie vertical stacks 2 sharp projectors with no rig so it could be fairly simple.
Top and bottom of a shelf, yeah... probably the best bet. Angle brackets on each side, above and below. I think that could work if I could rig something up that bolted their feet to the same threads?
 

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do you use SatCo or Adaptive Contrast? I think you said you were noticing some color shift using constant contrast? You said you have the gamut set to native and not pce right? And were you set to madvr-limited, nvidia-rgbfull, runco-rgbvideo?

When you redo the 3dlut, maybe reinstall displaycal and go into windows color management and ensure any profiles are loaded. Then make sure you dont do that 1dlut.

How did you have the meter positioned before? The 1dlut might have been the only issue but im curious, as with that paint there may be reduced offaxis gain so if the meter is lower than the center of the screen and pointed up towards the center it can skew the measurement.

Do you find light output adequate with SDR material? What are your contrast/brightness/gamma settings?
SatCo, no. Adaptive, yes/no. Constant Contrast, yes/no. Tried a bunch of stuff. Native gamut. Limited/full/limited.

Meter is positioned slightly under the middle of the screen, as you say, and I do wonder about the retroreflective nature of the painted material. I'll try it again as you suggest.

I think it's plenty bright, yeah. Even HDR stuff looks pretty decent.
 

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Discussion Starter #1,709
Top and bottom of a shelf, yeah... probably the best bet. Angle brackets on each side, above and below. I think that could work if I could rig something up that bolted their feet to the same threads?
i have no experience with stacking. would you be able to access the bottom projectors lens shift? Are you at the wide end of the lens and is there any barrel/bow distortion? Would lens samples and chromatic abberation effect focus and blending?

SatCo, no. Adaptive, yes/no. Constant Contrast, yes/no.
Gotcha, satco is brilliant color/rgbyc color cycling avoid that, adaptive contrast is a personal preference off is correct though, constant contrast is the led dimming so use when you want a better black but keep it off for measurements. I found 8x/medium to be a bit too aggressive in some scenes resulting in alot of compression, but 4x/low worked well.

Just out of curiosity what do you have the contrast setting at? not constant contrast, the regular one.
 

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i have no experience with stacking. would you be able to access the bottom projectors lens shift? Are you at the wide end of the lens and is there any barrel/bow distortion? Would lens samples and chromatic abberation effect focus and blending?
These are things I do not know. I imagine that it isn't easy. Maybe it's impossible. I don't see any distortion... throw is about 14'.

Just out of curiosity what do you have the contrast setting at? not constant contrast, the regular one.
Right now it's back at 100 because I have started over several times.
 

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Discussion Starter #1,711
Right now it's back at 100 because I have started over several times.
on the q750i I had contrast could be left at 100 without clipping. Brightness needed to go up a bit or there was some black crush, i dont remember at what point brightness would cause 0 ire to dither though. Thats generally how ill set those, contrast as high as itll go without clipping 232-234, and brightness up until just before 0ire dithers or set properly so it doesnt crush 17-18.

I didnt use satco or adaptive contrast, constant contrast on low(or off), 2.2 gamma. that should be fairly close to correct, then do the 1 point white balance in hcfr, leave the gamut on native and do the 3dlut and you should be golden.
 

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I watched Alita 2 nights ago in 3D, and DAMN dude. Thats the only way to watch that movie. I had seen it once before in UHD, but this was something else. Really enjoyed it.

Will have to grab RP1, I dont have that in 3d.

Any other must haves Jason?

btw when you run 3d stack, how are you doing it, are both projectors frame synced and you are just running regular 3d active?
Ready player one in 3D is amazing. I had seen it in 4k two years back it was good.. But then I saw it in 3D last month and is now one of my favorites.. I saw the 3D version 3 times in a week...

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Ready player one in 3D is amazing. I had seen it in 4k two years back it was good.. But then I saw it in 3D last month and is now one of my favorites.. I saw the 3D version 3 times in a week...

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How bout Prometheus in 3D, the snowy forest in therons ship looks really cool xD a 3d display within a 3d display, the depth!
 

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I think I'm gonna give up on this 3D LUT. Either my meter is wonky, or my painted DIY screen refuses to cooperate, or I'm just a moron.

Spent some time dialing in the greyscale with HCFR, everything looking good. Tried again... no dice. At least it already looks pretty great? Hrm.
 

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I think I'm gonna give up on this 3D LUT. Either my meter is wonky, or my painted DIY screen refuses to cooperate, or I'm just a moron.

Spent some time dialing in the greyscale with HCFR, everything looking good. Tried again... no dice. At least it already looks pretty great? Hrm.
can you post screenshots of the displaycal tabs?
 

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How bout Prometheus in 3D, the snowy forest in therons ship looks really cool xD a 3d display within a 3d display, the depth!
Yeah that was excellent. Seen that movie way too many times already need a few years breal before i watch it again.. what theh need to do is make a Prometheus 2..

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what theh need to do is make a Prometheus 2..
Alien: Covenant?

Watched the uhd copy of prometheus last night, and while not the same depth as the 3d version, some real upticks in detail like holloways face right before hes about to get torched. Really the whole movie despite being an upscale the 10bit p3 format looks really great.
 

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Discussion Starter #1,720
is there a bt2020 cie chart test pattern?
 
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