JVC RS4500 (native 4K laser projector)

[jetsen]

Have you tried different laser dimming modes?  Perhaps one of them is crushing blacks?

Tried about every combination possible but keep having the same result.

[kohe321]

If you have a proper camera with manual controls, you could try and take a picture of the screens with both projectors showing the same image. If you raise the exposure to the point where the camera does not crush any details itself (which an iphone or anything like that will do), perhaps this could show if one is displaying pixel information in shadows that the other is not.

Running back and forth while trying to remember what you saw sounds kind of difficult.

[AVSCraig]

If you have a proper camera with manual controls, you could try and take a picture of the screens with both projectors showing the same image. If you raise the exposure to the point where the camera does not crush any details itself (which an iphone or anything like that will do), perhaps this could show if one is displaying pixel information in shadows that the other is not.

Running back and forth while trying to remember what you saw sounds kind of difficult.

Ya, but a great way to get some exercise while watching video !

[AVSMike]

I can't get over the feeling that i am losing some details in the black levels, both the Murideo pluge and the Masciola patterns resolve 17 and clip 16 so everything seems ok with test pattern. But compared to the Epson for instance i get more shadow detail.

I have set gamma at 2.2 but tried to push the black in the Gamma setting to +6, just by looking at the picture that seems to work out better for resolving shadow detail.


I will measure the gamma curve both with the slider to 0 and to +6 to see the results, does anyone has the same feeling about the black levels or am I just seeing ghosts?

For those following along, Jetson posted this response to his above post:

By Jetsen
"I think its more me being paranoid, I am running between two rooms because the Epson and the Z1 are on different home cinema's. I just put the same still of a movie on both machines and ran like crazy from one room to the other, I know I know its not the way to do this and i should know better but I did not have the time to move one.

So for now lets keep it to me being paranoid, but if you guys could also verify it would make me mote at ease "

[AVSCraig]

Tried about every combination possible but keep having the same result.

I don't recall Kris mentioning this. You should email him or PM him and see what settings he is using compared to you.

[lygren]

Keep seeing that laser dimmer going bananas way too much... Seems to be worse in laser mode 2, but is certainly dims very weird in mode 1 as well... Hopefully this will be addressed in a firmware shortly though, seems really more like a bug than a "feature" to me... The Epson laser also uses laser dimming, but is not bouncing back and forth like this in regular scenes, however the "fade to black" on the Epson is very visible compared to the JVC.

[mark_h]

Looks like I'm joining the fun (frustration?), as I am now expecting installation this afternoon 

[ARROW-AV]

I have set gamma at 2.2 but tried to push the black in the Gamma setting to +6, just by looking at the picture that seems to work out better for resolving shadow detail.... I will measure the gamma curve both with the slider to 0 and to +6 to see the results, does anyone has the same feeling about the black levels or am I just seeing ghosts?

There are some things to be aware of regards the set up and calibration of this projector which can cause detail loss at both ends of the spectrum, but are resolvable... I will include the details within my report that I am in process of completing for posting on here later...

[jetsen]

There are some things to be aware of regards the set up and calibration of this projector which can cause detail loss at both ends of the spectrum, but are resolvable... I will include the details within my report that I am in process of completing for posting on here later...

If you are talking about the white clipping and Super white function, I know ;-)

[ARROW-AV]

If you are talking about the white clipping and Super white function, I know ;-)

Ha! I never doubted you didn't Werner! Nothing gets past your radar, that's for sure!

With respect to that particular matter I've already fed back to JVC the suggestion that they might like to change the factory default setting via the next firmware update such that the default is the correct setting, because I have a feeling, and I am sure you will agree, that there's going to be more than a few instances of consumers viewing their shiny new JVC RS4500/Z1 without any highlights detail above 235 because of this... But not your customers of course 

[mark_h]

I've always clipped my projectosr above 235 to preserve brightness.  For SDR, I'd be inclined to do the same, even with the Z1.   We shall see, I guess. 

Just took a final reading off my Sony 1000.  6.5fL off my screen in HIGH mode    The most I've ever achieved in my room is a blinding 11fL, and immediately down as the bulb dims.   Looking forward to see what I can squeeze out of the Z1.  Two hours ETA. 

[ARROW-AV]

I've always clipped my projectosr above 235 to preserve brightness.  For SDR, I'd be inclined to do the same, even with the Z1.

Good idea. Where brightness is a limiting factor that's certainly an option, but personally I am a detail freak... I just can't stand crushed shadow detail or clipped/blown highlights... I remember the gentleman who runs the THX professional video calibration opening the training by apologising to the whole class that he was going to forever after ruin our enjoyment of watching movies because we would not be able to view an image ever again without seeing everything that wrong with it such as in this regard, and unfortunately he was right... I've been totally screwed ever since

We shall see, I guess... Just took a final reading off my Sony 1000.  6.5fL off my screen in HIGH mode    The most I've ever achieved in my room is a blinding 11fL, and immediately down as the bulb dims. Looking forward to see what I can squeeze out of the Z1. Two hours ETA.

I am very much looking forward to your feedback in particular given the nature of your environment and especially your screen size and how you manage to get the Z1/RS4500 to perform with it

[mark_h]

Good idea. Where brightness is a limiting factor that's certainly an option, but personally I am a detail freak... I just can't stand crushed shadow detail or clipped/blown highlights...

Well, I would never deliberately crush blacks.  But for SDR, clipping above 235 is fine; been viewing digital films for 18 years now and never missed the details up there.  Of course, if I have more than enough light to hit my targets AND preserve the 235+ space then, why not?

I am very much looking forward to your feedback in particular given the nature of your environment and especially your screen size and how you manage to get the Z1/RS4500 to perform with it

Me too! 

[jetsen]

At the moment i am at mid laser, iris closed down to -7 and getting 16.5 Ftlmb on my 9ft acoustic 4K clear pix screen.
Adjusted the gamma to custom 2.3 and raised the gamma black level up to +1, I must say that you get use to having a decent amount of light output without thinking you are burning lamps like crazy ;-)

I think i will settle at this light output for a few movies and see what that gives, in HDR I am now at full open iris in mid laser but don't know if that will be sufficient, did not have time to actually watch some movies in that setting.
Can anyone chime in on wat you guys have  settled for in laser/iris settings and corresponding light output on some different screen sizes?

[AVSCraig]

Keep seeing that laser dimmer going bananas way too much... Seems to be worse in laser mode 2, but is certainly dims very weird in mode 1 as well... Hopefully this will be addressed in a firmware shortly though, seems really more like a bug than a "feature" to me... The Epson laser also uses laser dimming, but is not bouncing back and forth like this in regular scenes, however the "fade to black" on the Epson is very visible compared to the JVC.

That's interesting, as Kris said he couldn't see the laser dimming work while watching movies unless he really looked for it. I wonder why yours seems less well behaved ?