JVC RS4500 (native 4K laser projector)

[AVSCraig]

Oh believe me, I know.  My RS1 had 15k native contrast (according to specs).  The RS4500 is, what, half that?

I assumed it would at least beat the contrast of my 10 year old Sim2, but it's a lot closer than I hoped.  I just didn't expect the bright corners.

I haven't seen bright corners on mine, just FYI. Hopefully you only see them on test patterns.

[Pultzar]

I have an RS1 now so could probably go to the RS4500 without being annoyed by the lack of contrast.  But going from an RS620 seems like it might be a difficult compromise.

[Madfloyd]

What your actual native contrast will be all depends on what aperture setting you are using. WORST case is around 8K:1. But if you are using the aperture it is probably higher. I am getting about 14,000:1, but with the RS620 I was getting closer to 60K:1 in my setup native (way higher than that with the DI engaged).

Thanks for the clarification.  Ken didn't measure the contrast and I thought it only improved with the dynamic laser, so I will now assume that with the aperture at -7 (which is where I have it) that the contrast is higher than 8k.

[Madfloyd]

I haven't seen bright corners on mine, just FYI. Hopefully you only see them on test patterns.

I see them on black scenes (e.g. fade to blacks).

[Kris Deering]

I have an RS1 now so could probably go to the RS4500 without being annoyed by the lack of contrast.  But going from an RS620 seems like it might be a difficult compromise.

Yes and no. There are trade offs with everything. If I had a smaller screen than the 620 is a no brainer. With a larger screen I started bumping into sharpness benefits. The RS4500 shows a noticeable bump in resolution with both Blu-ray and UHD playback. But neither projector disappoints!

[AVSCraig]

I have an RS1 now so could probably go to the RS4500 without being annoyed by the lack of contrast.  But going from an RS620 seems like it might be a difficult compromise.

Only on a few scenes ( I'm coming from an RS600 ) do I wish I had more contrast. Most of the time things look better - cleaner image than the RS600, and 4k looks outstanding. It's just the rare scene that you can tell that there is less contrast. Hell, I even put " Dark City " on, and it look pretty darn good !

[Madfloyd]

Only on a few scenes ( I'm coming from an RS600 ) do I wish I had more contrast. Most of the time things look better - cleaner image than the RS600, and 4k looks outstanding. It's just the rare scene that you can tell that there is less contrast. Hell, I even put " Dark City " on, and it look pretty darn good !

Ooooh, Dark City, there's a good one to try.

Yeah, there's no question that coming from an RS1 you'd be thrilled with the RS4500 (as you darn well should be!).  I still have my RS1 and while it's still hooked up and watchable (in a smaller room upstairs), I rarely do as I'd have a hard time with the lack of detail (by comparison).

[Kris Deering]

The RS1 vs RS4500 is literally night and day difference. Never mind the increase in just about every way (optics, resolution, contrast, motion resolution, lamp stability) but also the accuracy of image. The RS1 and RS2 were horrible for flesh tones and accuracy overall. The RS1 doesn't stack up well to any of the modern JVCs.

[AVSCraig]

I got the 4500 up on Saturday. Have had a long weekend due to the back issues, which are slowly getting better. I'm seeing some weird results with the new dynamic laser implementation. If anyone here on the forum can help, I'd like them to look at two different scenes for me. Using the Blu-ray's of Star Wars The Force Awakens and Oblivion, send 1080p to the 4500 (not scaled to 4K). For Star Wars watch the opening sequence after the title crawl with the ship's shadow covering the planet and the small ships appearing from behind it. How does the dynamic laser do with this scene in your setup? For Oblivion, how does it do with the opening credits that are right after the Universal logo and before the flashback (there are only a few)? Any feedback on these would be appreciated.

So I just watched these scenes, but let my UB900 send upscaled 4K. I also used the Oblivion Blu-ray rather than the 4K disc.

Star Wars : The Force Awakens. the title crawl looks just like all the other movies - title lines are fairly bright yellow, and slowly fade into the background until they are so small I can barely see them. I don't see the dynamic iris work at all. I watched until the attack on the planet. The small ships coming around the large ship look spectacular - they are fairly bright. Once the large ship fills the screen, there is good shadow detail. Didn't see the dynamic iris work once during the first 5 minutes.

I watched " Memento " tonight, and I did see the iris trip up a few times, so it is working.

" For Oblivion, how does it do with the opening credits that are right after the Universal logo and before the flashback (there are only a few)? Any feedback on these would be appreciated. " - two scenes of one line each of white credits on a black background. Doesn't look any different than if I watched it on my RS600. No iris detected. Then the B & W flashback scene. I watched the credit twice just to be sure. Looks like white credits on a black background. Nothing unusual.

[mark_h]

I have the weirdest issue that is driving me nuts and in the off chance that someone here can shed any light on it, I'm going to mention it.  It shouldn't be related to my new projector but the problem surfaced when the RS4500 arrived on the scene.   My FIOS Motorola STB has a lip-sync problem that is very severe.  It turns out the audio is delayed so I can't correct via the typical lip-sync features in my pre/processor.  There don't seem to be any settings in the STB that I can look to for a cure and googling hasn't helped.  Any ideas?   Why this would happen when I switch projectors I cannot figure out (all other sources are fine, including others going through the pre/processor).

The Z1 added a lot of extra a/v delay to my setup and I had to remeasure and correct to remove lipsync issues...

[Madfloyd]

The Z1 added a lot of extra a/v delay to my setup and I had to remeasure and correct to remove lipsync issues...

When you say 'remeasure' is there a way to do this?  When the video is delayed, can one correct that in a device like a Lumagen (I'm just curious, not about to buy a Lumagen for TV, lol).

[Kris Deering]

So I just watched these scenes, but let my UB900 send upscaled 4K. I also used the Oblivion Blu-ray rather than the 4K disc.

Star Wars : The Force Awakens. the title crawl looks just like all the other movies - title lines are fairly bright yellow, and slowly fade into the background until they are so small I can barely see them. I don't see the dynamic iris work at all. I watched until the attack on the planet. The small ships coming around the large ship look spectacular - they are fairly bright. Once the large ship fills the screen, there is good shadow detail. Didn't see the dynamic iris work once during the first 5 minutes.

I watched " Memento " tonight, and I did see the iris trip up a few times, so it is working.

" For Oblivion, how does it do with the opening credits that are right after the Universal logo and before the flashback (there are only a few)? Any feedback on these would be appreciated. " - two scenes of one line each of white credits on a black background. Doesn't look any different than if I watched it on my RS600. No iris detected. Then the B & W flashback scene. I watched the credit twice just to be sure. Looks like white credits on a black background. Nothing unusual.

That's exactly what I'm seeing if I send the video via 4K. You should take a look at the same scenes in 1080p and see how much difference it makes! Nasty dynamic dimming artifacts!

[Madfloyd]

I wonder when we'll see further firmware updates by JVC.    This dynamic laser issues seems not so much the result of a performance tweak but an actual software bug that should be addressable.

[AVSCraig]

That's exactly what I'm seeing if I send the video via 4K. You should take a look at the same scenes in 1080p and see how much difference it makes! Nasty dynamic dimming artifacts!

You are making me scared to see that !    I  wonder why the difference. One thing - my HDTV feed is 1080i ( or whatever they send ) and I do not see dynamic dimming problems with that. I do watch a few things like " Nova " that has scenes that could trip it up. 

I'm happy with the Panasonic UB900 upscaling Blu-rays to 4K, and you just gave me another reason not to change it.

[AVSCraig]

When you say 'remeasure' is there a way to do this?  When the video is delayed, can one correct that in a device like a Lumagen (I'm just curious, not about to buy a Lumagen for TV, lol).

My Denon X7200WA has audio delay for each source, so that's how I'm going to do it. Haven't got it totally dialed in yet though. One interesting thing - it seemed like turning on CMD to high improved audio sync, and it didn't have any affect on the picture ( since it's already shot on video, at least what I watched at the time ).