JVC RS4500 (native 4K laser projector)

[mark_h]

From what i read here it seems everybody is running 1080P Blu ray on this projector, as it seems its not capable of delivering any usefull lightoutput while maintaining a decent black level for UHD mastered content.. Or am i missing something.?

I've viewed 4K/SDR and it looks absolutely stunning.   Not enough light on my screen for HDR, or even 2020.

[Highjinx]

THIS is precisely the root cause of the issue in our opinions as well And I had a chat a while back with Alan Gouger and (if he doesn't my saying so) this is his opinion too... So NAIL... HEAD... HIT

IMO in hindsight JVC should have simply made the panel 4 times the size whilst retaining the same pixels size, or even better made the panel 5 times the size with 20% larger pixels size for even better raw contrast performance as compared with the HD panels... Hopefully JVC or at the very least another manufacturer will realize this and do precisely this .

Sometimes reading things on the internet makes it hard to decipher when someone is joking or not. I assume you aren't serious about making the panels that much larger, are you? A 5 times larger panel would mean each DiLA chip was almost 3.5" in size. The exit element of the lens is only a little larger than this. Do you know how big the optics would need to be for 3.5" DiLA panels? 

There must be an optimal target ratio the need to adhere to, but these wafers are quite expensive around $1200-$1500 processed for a 200mm wafer (costs could be less now)

JVC no doubt settled for the most cost effective size, but post development realized the massive drop in their cherished spec - native contrast.

Time for a rethink of light engine design>

Phosphor tipped 3mm dia Laser diode>30 approx .5mm optical fibre optical cables attached to each phosphor laser diode>solid state light gates to each optical cable with a polarizer stage>output(direct or via optical cable)to chip.

Individual laser diodes can be modulated as well as each optical fibre path.

Assuming 12 laser diodes per primary color, this will give 360+ zones of dimming. HT projector HDR Nirvana.

This will give the more expensive models with more laser diodes more modulatable zones. Win/win.

 

[ARROW-AV]

Sometimes reading things on the internet makes it hard to decipher when someone is joking or not. I assume you aren't serious about making the panels that much larger, are you? A 5 times larger panel would mean each DiLA chip was almost 3.5" in size. The exit element of the lens is only a little larger than this. Do you know how big the optics would need to be for 3.5" DiLA panels? 

I think you need to change the batteries in your calculator Dylan

And YES I am absolutely one hundred percent serious about making the panels that much larger

Here's the figures:

DIAGONAL    0.69 INCHES
WIDTH    0.60 INCHES
HEIGHT    0.34 INCHES
AREA            0.20 SQUARE INCHES
      
AREA x 4    0.81   SQUARE INCHES
LENGTH    1.20   INCHES
WIDTH    0.68   INCHES
DIAGONAL 1.38    INCHES
      
AREA x 5   1.02   SQUARE INCHES
LENGTH   1.34   INCHES
WIDTH   0.76   INCHES
DIAGONAL   1.54   INCHES

So, we are in fact talking about 1.38" / 1.54" DiLA panels, not 3.5"

You're welcome .

[stridsvognen]

I've viewed 4K/SDR and it looks absolutely stunning.   Not enough light on my screen for HDR, or even 2020.

I done some testing myself running UHD SDR from the UB900, and playing with the HDR to SDR converter and personally i found that around 60fl was needet to give UHD SDR some kind of extra to offer over normal HD.. So i always wonder how people get away with UHD SDR with 15-25fl  Do you have some external processor, or a feature in the projector that further compresses the highlights without clipping white to alow the average image to look punchy and maintain low level information.?  If im not much mistaken HD is mastered to around 100nit/ 30fl wich in most cases is a hard target to reach for most projectors.. But i do agree that there is extra information and dynamic on UHD that pops on a capable display, even on a 1080P REC 709 display if it will just output enough light to hit a gamma curve out of black, and maintain a black black level, that makes the SMPTE 2084 mastered movie presentation look somehow like they were intendet.

[mark_h]

What display are you using...?

[AVSCraig]

Not quite sure what that is supposed to mean...?  I've been through many projectors in my room...

When you said it was the best image you've had in your theater, I was just wondering what the other projectors you had owned in the past - that's all.

[mark_h]

When you said it was the best image you've had in your theater, I was just wondering what the other projectors you had owned in the past - that's all.

Well, I suppose it's enough to know that the Sony 1000 was the best I'd seen previously, and the Z1 is very likely to replace it.  I'll keep the Z1 for a year or two until either a) Sony prove their SXRD no longer degrade and replace the 5000, or JVC come out with a Z2 that delivers what we all wanted from the Z1!

[stridsvognen]

What display are you using...?

Mostly tested it on a Pioner plasma, that maxed out at 60fl calibrated without compromising the black level. I have a CRT projector that is normaly shooting 14fl, and can do 20fl with scope movies.. And dont get much pleasure from the UHD SDR, as ill need to set the HDR converter to clip white to get a decent average light output, so im curious how you get around the limited light output and make UHD SDR better than HD.

[AVSCraig]

Mostly tested it on a Pioner plasma, that maxed out at 60fl calibrated without compromising the black level. I have a CRT projector that is normaly shooting 14fl, and can do 20fl with scope movies.. And dont get much pleasure from the UHD SDR, as ill need to set the HDR converter to clip white to get a decent average light output, so im curious how you get around the limited light output and make UHD SDR better than HD.

With neither of those displays being 4K ( correct me if I'm wrong ), I'm not sure why you would even bother trying to view 4K source material on them. I can easily see a picture improvement on my JVC RS600 ( which while not native 4K, can display 4K ) over standard Blu Ray, and I'm expecting the RS4500 / Z1 to be even better. Mostly with 4K SDR BT.2020, but I might change that with the RS4500.

[AVSMike]

Therefore, it DOES NOT have infinity : 1 native contrast Mike, so JVC should not state that it does in the published technical specs...

I agree. That is why I said, I don't know why it has not been changed in the spec.

[stridsvognen]

With neither of those displays being 4K ( correct me if I'm wrong ), I'm not sure why you would even bother trying to view 4K source material on them. I can easily see a picture improvement on my JVC RS600 ( which while not native 4K, can display 4K ) over standard Blu Ray, and I'm expecting the RS4500 / Z1 to be even better. Mostly with 4K SDR BT.2020, but I might change that with the RS4500.

Oposit most people today i dont realy care about the pixel count, im into image quality, not pixels.. So it there is a advantage in a format i dont mind using it.. No matter if its a HD or UHD display everything other than the pixel count apply the same, that beeing the SMPTE 2084, and whatever color gammut used.. So testing on a 1080P display outputting 1080P SDR REC 709 is no different than a 2160P SDR rec 709 in regard to gamma and colors..

UHD is still 4:2:0 wich when downscaled to 1080P should be possible to get a perfect non upsampled 4:4:4 croma, and my main issue with HD is not the resolution, but the compression who needs croma upsampling.. UHD have more low level information mastered into the movies, but you need the right ramp out of black to take advantage of it. If you come out of black to flat it dont work.. so therefore you need to somewhat follow the SMPTE 2084 gamma out of black, and compress the highlights.. But a UHD movie displayed on a HD calibrated display looks terrible dim and flat, and they are 2 different ways of mastering, so im curious how you guys get around the low light output, and maintain the SMPTE 2084 gamma curve and average light output, as i would like to try that myself, so when people tell that UHD SDR looks great, or better than HD ill expect they did some work to get there, and can explain what.

[Dylan Seeger]

I think you need to change the batteries in your calculator Dylan

And YES I am absolutely one hundred percent serious about making the panels that much larger

Here's the figures:

DIAGONAL    0.69 INCHES
WIDTH    0.60 INCHES
HEIGHT    0.34 INCHES
AREA            0.20 SQUARE INCHES
      
AREA x 4    0.81   SQUARE INCHES
LENGTH    1.20   INCHES
WIDTH    0.68   INCHES
DIAGONAL 1.38    INCHES
      
AREA x 5   1.02   SQUARE INCHES
LENGTH   1.34   INCHES
WIDTH   0.76   INCHES
DIAGONAL   1.54   INCHES

So, we are in fact talking about 1.38" / 1.54" DiLA panels, not 3.5"

You're welcome .

I really wasn't thinking that one through. I just multiplied the diagonal length times 4 and 5. Figuring out the surface area didn't even occur to me. DOH!

With that said, the argument is still essentially the same. Getting the display area that large brings you into the commercial projector realm and as such necessitates much larger light engine optics and prime lenses. I don't think it's feasible for the consumer market. JVC will have to figure something else out especially when most are buying projectors in the under $5000 market. 

[ARROW-AV]

I really wasn't thinking that one through. I just multiplied the diagonal length times 4 and 5. Figuring out the surface area didn't even occur to me. DOH!

No worries Dylan, I am by no means perfect and suffer the occasional brain-fart. It's to be expected when we get to our age! So you are forgiven already

With that said, the argument is still essentially the same. Getting the display area that large brings you into the commercial projector realm and as such necessitates much larger light engine optics and prime lenses. I don't think it's feasible for the consumer market...

Not quite... Your argument is that it will not be even close to economically viable to do as I have suggested... But this is not factually correct.

When you take in consideration what will be the actual correct size of the larger panels, the manufacturing cost implication, the target demographic, and the considerable selling price headroom that exists between the JVC RS4500/Z1 and the SONY VPL VW5000ES, and do the maths (as I have done so) it would in fact be possible for JVC to release a projector such as the Z1 but with the x4/x5 panel sizes for a selling price the same as the SONY 5000ES

It strikes me that the RS4500/Z1 would appear to fall between two chairs, as more than one person has observed, in other words who is its target demographic exactly? It's certainly not going to be a product that can directly compete with the SONY 5000, which is what we were informed by JVC was a primary objective when it was announced.

And whilst it's clear that you can obtain a nice looking image, this is not without being agreeable to compromise in more ways than one, either by limiting the screen size, or accepting less than THX recommended guidelines with respect to video performance.

So, aside from being a bit of a misfire performance-wise it would appear to be a bit of a marketing misfire too, because in order to properly compete with the SONY 5000, which was/is the intention here, we are of the view that JVC should have opted for producing the best product for the same price as the SONY 5000, instead of trying to significantly undercut it on price and outperform it at the same time... But where the poor contrast and brightness performance of the 0.69" native 4K chip/panel has kiboshed the whole product unfortunately.

And I am sure I am not the only person of the opinion that the fundamental mistake here was/is reducing the contrast performance at the component level, especially taking into consideration:
(1) Superior black levels and contrast is JVC's primary USP with its consumer HT projectors; and
(2) Being a new premium flagship product costing $35,000 customers are not going to be happy about having significantly worse black levels and constrast as compared with their existing HT projectors.

Therefore, I come back to the fact that for this product to meet its intended marketing plan including target demographic, reducing the size of the display panels by a factor of 4 and thereby the size of the pixels and thereby the contrast/pixel performance was/is the root cause of the problem here and as such a fundamental mistake by JVC.

Wherein, all that needs to be done to address and fix the problem is to change these awful 0.69" 4K DiLA panels/chips with the 1.38" / 1.54" size 4K DiLA panels that I have mentioned. And where the good news is that it is both practically and theoretically potentially economically viable to do so, given the headroom available allows the selling price to be increased by up to x1.714

Can anyone point me in the direction of JVC's suggestions box?
 

[ARROW-AV]

Well, I suppose it's enough to know that the Sony 1000 was the best I'd seen previously, and the Z1 is very likely to replace it.  I'll keep the Z1 for a year or two until either a) Sony prove their SXRD no longer degrade and replace the 5000, or JVC come out with a Z2 that delivers what we all wanted from the Z1!

Thanks for all your brilliant feedback Mark!

I have been most interested reading all your posts on both here and the 'other' forum... But in particular because your fabulous home cinema/theater that you have there most closely mirrors my own, that I have as my own point of reference, where in addition to being a blacked out room like yours, both the screen size and gain are almost identical as yours, and the projector is also identical (Sony 1000), and you've even got what is essentially identical calibration kit as me too!

So it's interesting to see that your measurements are essentially the same as mine, and whilst it's disappointing that the contrast and brightness performance measurements in particular are a bit disappointing and do not meet expectations, overall you can achieve a very nice looking image and if one does not get hung up on the particular figures overall image-wise it could be considered a pretty decent upgrade from what you have experienced with the Sony 1000 on that screen size in your environment. My point being it can be easy to focus solely on fact and figures but it's not all doom and gloom in that the image produced by this projector when set up properly and in the right environment is not only comparatively quite lovely but also impressive, and from the sounds of it a step up from what you had previously which is certainly a good thing!

And I should add that I know you are (understandably) not a fan of lamp-based projectors and so in this respect alone the RS4500/Z1 is a significant upgrade!

That said, like you I am looking forward to the next projectors down the line which offer yet even better performance

Enjoy!

[Andreas21]

Oposit most people today i dont realy care about the pixel count, im into image quality, not pixels.. So it there is a advantage in a format i dont mind using it.. No matter if its a HD or UHD display everything other than the pixel count apply the same, that beeing the SMPTE 2084, and whatever color gammut used.. So testing on a 1080P display outputting 1080P SDR REC 709 is no different than a 2160P SDR rec 709 in regard to gamma and colors..

UHD is still 4:2:0 wich when downscaled to 1080P should be possible to get a perfect non upsampled 4:4:4 croma, and my main issue with HD is not the resolution, but the compression who needs croma upsampling.. UHD have more low level information mastered into the movies, but you need the right ramp out of black to take advantage of it. If you come out of black to flat it dont work.. so therefore you need to somewhat follow the SMPTE 2084 gamma out of black, and compress the highlights.. But a UHD movie displayed on a HD calibrated display looks terrible dim and flat, and they are 2 different ways of mastering, so im curious how you guys get around the low light output, and maintain the SMPTE 2084 gamma curve and average light output, as i would like to try that myself, so when people tell that UHD SDR looks great, or better than HD ill expect they did some work to get there, and can explain what.

When watching UHD with SDR you no longer have to think about st2084 as with SDR you use the normal SDR gamma you prefer. And the best way to watch UHD movies (this is my personal opinion) on a projector so far is to use rec709 and SDR as this will give you the most accurate picture. When using rec2020 and SDR  it messes up the gamma in some ways, and also the colors are affected. So I watch UHD movies in rec709 and SDR and get 4K resolution and 10bit and to me this looks a little better than normal BD, but not much. I watch 99% BD on my MadVR High End PC with a watercooled Titan X Pascal GPU.