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NEW RANGE JVC 2014 - Page 44

post #1291 of 3991
Quote:
Originally Posted by JonStatt View Post

We know that the new range now enable CMD in 3D although whether that will be a benefit or a curse for 24p 3D I don't know.

But I don't think it has been answered if e-shift now works in 3D


That would be an exciting thought Jonathan but sadly I believe Manni is (as usual) correct. Like you pointed out a few years back when we spent so much time anal-yzing over eShift's hard pencil ghosting on those tough scenes, unless the panels are sped up we will most likely be stuck with a bit of ghosting with this versions.
post #1292 of 3991
Quote:
Originally Posted by mark haflich View Post

Using my 4K 1000ES, subpixels adjustments are in tenths of a pixel.

There you go again… dropping that 1K-4K machine in our face! Go-head… rub it in. tongue.gif

Speakin' of rubbing the poo… 3-2 lead now… What a WEIRD series (but really great)! One more to go my man!! wink.gif
post #1293 of 3991
Quote:
Originally Posted by R Harkness View Post

I'm in video-processor research mode because I want to be able to self-calibrate my projectors (and also try some of the auto-cal processes), hence looking at Lumagen.

If I bought one of the new 4K upscaling Lumagen VPs, is there any reason why it shouldn't work with one of these new JVC projectors? I know it's dubious that the 4K input capabilities of the JVCs will meet future native-4K-content specs. But they should be good for at least accepting upscaled 1080p to 4K content from a VP like the Lumagen, right?

If calibration is all you're interested in then I'd rather use an eeColor box. It allows a more detailed calibration than the Lumagens (65^3 instead of 9^3) and is cheaper. Neither the Lumagen nor the eeColor box currently support 4K input, though, I think? So if you want to calibrate 4K sources you'll probably have to upgrade the Lumagen or the eeColor box in the future again.

But yes, the Lumagen 4K output should be accepted by the new JVCs. Whether you'll see an improvement in scaling quality or not nobody can say for sure right now. We'll have to wait for real end user (or reviewer) reports on that.

If you're using an HTPC you could also let the HTPC calibrate and upscale to 4K. But that would then only work for HTPC sources, not for external sources (settop box etc). So this is probably an option only for people who drive their projector exclusively with their HTPC.
post #1294 of 3991
Mark and I have exchanged views on the fine convergence adjustment previously and are totally in agreement.

On the JVCs, for whatever reason the adjustment is in 1/16s of a pixel. So a shift of 8 points in any direction means half a pixel. If you go into the service menu and display the convergence test pattern with separated red, green, blue lines, you will see that the colour you adjusted to 8 now has two rows or columns of pixels instead of 1. Congratulations you have just halved the resolution of that colour! Naturally this is a worst case scenario, but you can evaluate the effects of other positions through simple math anyway. So if you adjust 4 points in any direction then you have reduced the resolution of that colour by a quarter.

As Mark says, a 1 or 2 point adjustment probably had little bearing on the perceived resolution or sharpness of the image. However, my viewpoint has always been very clear on this.

Use whole pixel shifts only for the central region of the screen such that you get it within 0.5 a pixel. And only use the fine convergence adjustment towards the edges to avoid visible fringing.

As usual I remind everyone that the two most critical colours to converge are red and green. Blue really doesn't matter very much and will not affect perceived sharpness.
post #1295 of 3991
Quote:
Originally Posted by JonStatt View Post

Congratulations you have just halved the resolution of that colour!

Well, yes and no. You may have "halved the resolution" for the adjusted color channel in extreme computer graphics test patterns. But the situation is totally different for real film/photo material. There such convergence adjustments (if done right) should not harm resolution much.
post #1296 of 3991
Quote:
Originally Posted by madshi View Post

Well, yes and no. You may have "halved the resolution" for the adjusted color channel in extreme computer graphics test patterns. But the situation is totally different for real film/photo material. There such convergence adjustments (if done right) should not harm resolution much.

I don't follow. The test patterns are just a way of showing the effect of the change. The colour information for that colour has indeed been halved. This is not like some tests which produce weird effects only seen in test patterns. The effect of adjusting the convergence is unequivocal...the resolution is halved for that colour! Whether you can see it or not is a different matter, but the effect is not a "maybe".
post #1297 of 3991
Quote:
Originally Posted by madshi View Post

If calibration is all you're interested in then I'd rather use an eeColor box. It allows a more detailed calibration than the Lumagens (65^3 instead of 9^3) and is cheaper. Neither the Lumagen nor the eeColor box currently support 4K input, though, I think? So if you want to calibrate 4K sources you'll probably have to upgrade the Lumagen or the eeColor box in the future again.

But yes, the Lumagen 4K output should be accepted by the new JVCs. Whether you'll see an improvement in scaling quality or not nobody can say for sure right now. We'll have to wait for real end user (or reviewer) reports on that.

If you're using an HTPC you could also let the HTPC calibrate and upscale to 4K. But that would then only work for HTPC sources, not for external sources (settop box etc). So this is probably an option only for people who drive their projector exclusively with their HTPC.

The eecolor is not very good advice even for upscaled 1080p as it doesn't pass through 3D bluray (it's HDMI ports are HDMI 1.3). Its LUT tables are great for 2D, but for anyone wanting to passthrough bluray 3D it's a no-no.

The Lumagen do not have a 4K input yet, only some models have a 4K output (to upscale and calibrate 1080p and SD content).
post #1298 of 3991
Quote:
Originally Posted by JonStatt View Post

I don't follow. The test patterns are just a way of showing the effect of the change. The colour information for that colour has indeed been halved. This is not like some tests which produce weird effects only seen in test patterns. The effect of adjusting the convergence is unequivocal...the resolution is halved for that colour! Whether you can see it or not is a different matter, but the effect is not a "maybe".

Instead of trying to convince you with scientific arguments let's just do a simple practical test. Let me use the Gladiator Blu-Ray with the newer 4K scan which is nicely sharp and detailed. Please compare the following two images and tell me which is the untouched original image and which is the image which I have offset by half a pixel in both x and y direction? I've masked the black bars a bit to make it less obvious which is which. According to your theory moving a color channel by half a pixel halves resolution. In this Gladiator test I've moved all 3 RGB color channels by half a pixel in both x and y direction. So according to your theory resolution of the shifted image should now be a quarter of the original, I think. Is that what you're seeing in those images?

image 1 -- | -- image 2
post #1299 of 3991
Quote:
Originally Posted by Manni01 View Post

The eecolor is not very good advice even for upscaled 1080p as it doesn't pass through 3D bluray (it's HDMI ports are HDMI 1.3).

Oh, you're right, I forgot about that, thanks for the correction.
post #1300 of 3991
Quote:
Originally Posted by madshi View Post

Instead of trying to convince you with scientific arguments let's just do a simple practical test. Let me use the Gladiator Blu-Ray with the newer 4K scan which is nicely sharp and detailed. Please compare the following two images and tell me which is the untouched original image and which is the image which I have offset by half a pixel in both x and y direction? I've masked the black bars a bit to make it less obvious which is which. According to your theory moving a color channel by half a pixel halves resolution. In this Gladiator test I've moved all 3 RGB color channels by half a pixel in both x and y direction. So according to your theory resolution of the shifted image should now be a quarter of the original, I think. Is that what you're seeing in those images?

image 1 -- | -- image 2

I will have a look a bit later when I have a decent monitor to evaluate on. As they are .jpg I am not sure how much the compression will affect things anyway. Neither of the images look very sharp to me on my monitor right now so I will report back. Also if you have changed all 3 colours, I don't know if the JVC is clever enough to use relative displacement rather than absolute. Certainly when I have played with this before myself, I have moved green or red and I could see a slight softening of the overall image...but when I moved blue I couldn't see any difference. Thanks for taking the time and effort to do a test though.
Edited by JonStatt - 10/29/13 at 3:54am
post #1301 of 3991
Quote:
Originally Posted by JonStatt View Post

I will have a look a bit later when I have a decent monitor to evaluate on. As they are .jpg I am not sure how much the compression will affect things anyway. Neither of the images look very sharp to me on my monitor right now so I will report back. Also if you have changed all 3 colours, I don't know if the JVC is clever enough to use relative displacement rather than absolute. Certainly when I have played with this before myself, I have moved green or red and I could see a slight softening of the overall image...but when I moved blue I couldn't see any difference. Thanks for taking the time and effort to do a test though.

The images are PNG, not JPG. PNG is lossless. Make a screenshot of any sharp movie you like and I can repeat the same test for that movie screenshot.

It is possible that the JVC and Sony convergence correction algorithms are not well implemented, I don't know that. If you see a noticeable softening with real world material (movies) then that would suggest IMHO that the algorithm is not implemented as well as it could be. In any case, the key point I wanted to make is this: Computer test patterns don't represent real life material well, when doing image resampling/processing tests. If you shift computer graphic test patterns half a pixel, the image *must* get noticeably softer. No question about that, it's not possible any other way. But this doesn't apply to film/photo material. This has scientific reasons, but I prefer demonstrating it instead, because in my experience that is more convincing than explaining things with words.
post #1302 of 3991
Quote:
Originally Posted by pillimthb89 View Post

I have Calman 5 so the autoCal functionality isn't enticing, and although eShift is nice, I don't see much value in sending 4K input to a 2K machine...It's still getting down-scaled and averaged out for the eShifted "4K" image.9ebrkD

When fed 4K the new models do not downscale to 2K. They create two 1080p subframes directly from the 4K input. This is not the same as downsampling to 2K.
The benefit the 204x Lumagen could bring is better (ring free) upscaling and better calibration thanks to the 9x9x9 3D LUT.
Of course, as Madshi said, there is no way to know what the improvement actually is until we can assess both the way the new range upscales 1080p and the way the calibration tracks with the internal CMS.
If the internal upscaling is excellent and if the CMS is better than in the past and tracks very well, then the benefit from the Lumagen will probably be minimal.
If the internal upscaling adds some ringing and if the CMS doesn't track well as in the past, then the Lumagen could bring significant improvements to the picture.
post #1303 of 3991
Quote:
Originally Posted by madshi View Post

The images are PNG, not JPG. PNG is lossless. Make a screenshot of any sharp movie you like and I can repeat the same test for that movie screenshot.

It is possible that the JVC and Sony convergence correction algorithms are not well implemented, I don't know that. If you see a noticeable softening with real world material (movies) then that would suggest IMHO that the algorithm is not implemented as well as it could be. In any case, the key point I wanted to make is this: Computer test patterns don't represent real life material well, when doing image resampling/processing tests. If you shift computer graphic test patterns half a pixel, the image *must* get noticeably softer. No question about that, it's not possible any other way. But this doesn't apply to film/photo material. This has scientific reasons, but I prefer demonstrating it instead, because in my experience that is more convincing than explaining things with words.

Which model of projector were you making the adjustments with for those files?
post #1304 of 3991
Quote:
Originally Posted by madshi View Post

Oh, you're right, I forgot about that, thanks for the correction.

No problem, I only remember because I seriously considered the eecolor before finding out about this dealbreaker (to me) smile.gif
Edited by Manni01 - 10/29/13 at 4:21am
post #1305 of 3991
Quote:
Originally Posted by JonStatt View Post

Which model of projector were you making the adjustments with for those files?

Not sure what you mean? I've processed the image on my development PC with my own software. The point of my experiment was to prove that you can move color channels half a pixel without losing resolution - provided you use a good algorithm and you test with real movie content. With a bad algorithm and/or with computer graphics test patterns resolution can be lost. But it should be much less than "half the resolution" for real movie material even when using a bad algorithm.
post #1306 of 3991
Quote:
Originally Posted by madshi View Post

Not sure what you mean? I've processed the image on my development PC with my own software. The point of my experiment was to prove that you can move color channels half a pixel without losing resolution - provided you use a good algorithm and you test with real movie content. With a bad algorithm and/or with computer graphics test patterns resolution can be lost. But it should be much less than "half the resolution" for real movie material even when using a bad algorithm.

Sorry. I wasn't sure where/how you were manipulating the images. So it's all on your PC with your own software. Thanks
post #1307 of 3991
Quote:
Originally Posted by R Harkness View Post

I'm in video-processor research mode because I want to be able to self-calibrate my projectors (and also try some of the auto-cal processes), hence looking at Lumagen.

If I bought one of the new 4K upscaling Lumagen VPs, is there any reason why it shouldn't work with one of these new JVC projectors? I know it's dubious that the 4K input capabilities of the JVCs will meet future native-4K-content specs. But they should be good for at least accepting upscaled 1080p to 4K content from a VP like the Lumagen, right?

Personally, I'd either wait for a 4K Lumagen or get an XE, which IMO/IME should offer a potentially better upgrade path. A Lumagen is a pretty big investment (not like a Darbee) and I'd want to make sure I had a "plan" for upgrading to full 4k capability, not just 4k upconversion. This is part of the reason I opted for the XE when I got mine over the XS.
post #1308 of 3991
Quote:
Originally Posted by pillimthb89 View Post

I have Calman 5 so the autoCal functionality isn't enticing, and although eShift is nice, I don't see much value in sending 4K input to a 2K machine...It's still getting down-scaled and averaged out for the eShifted "4K" image.9ebrkD

The 4K input is not down-converted. With 1080P input, JVC upscales to 4K resolution in the projector using MPC. Then, JVC uses that 4K data to create an “A Frame” and a “B Frame”. The A Frame is different from the B Frame. Each frame is 1920 x 1080. The “B Frame” is shifted down and over by ½ a pixel. Those frames are projected at double speed. Your eyes and your brain blend them together to create the 4K e-shift image that you see on the screen.

With a 4K input, nothing is upscaled. The pixels needed for the “A Frame” are taken directly from the 4K data and the different pixels that are needed for the “B Frame” are taken directly from that same 4K data, using JVC's proprietary algorithm. The “A Frame” is different from the “B Frame”. Each frame is 1920 x 1080. The “B Frame” is shifted down and over by ½ a pixel. Again, those frames are projected at double speed. Again, your eyes and your brain blend them together to create the 4K e-shift image that you see on the screen.
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post #1309 of 3991
To chose an XE over a 4K out Lumagen at this point is bad invoice for a variety of reasons. Assuming one just needs 4 HDMIs in, the 2041 is cheaper than an XE, way cheaper, and one gets 4K non ring scaling, built in Darblet at the inputs, and the ability to do automated 729 point calibrations, none of which is possible with the XE. Plus there will be an upgrade path to the 4K in Lumagen when HDMI 2.0 chip availability allow it to come out. Rich give me a call when you can, there are a bunch of things I can't put in print. smile.gif
post #1310 of 3991
Quote:
Originally Posted by stanger89 View Post

Personally, I'd either wait for a 4K Lumagen or get an XE, which IMO/IME should offer a potentially better upgrade path. A Lumagen is a pretty big investment (not like a Darbee) and I'd want to make sure I had a "plan" for upgrading to full 4k capability, not just 4k upconversion. This is part of the reason I opted for the XE when I got mine over the XS.

I'm looking at the new Lumagen Radiance 2041, with the 4K outputs. It's been reported here, ok'd by Lumagen, that this unit will be user upgradable to native 4K input for a "modest" fee. So I think I'd be set pretty well if I go for it.

The reasons I'm looking at grabbing a Lumagen are:

1. Calibration. I want to be able to re-calibrate my existing projector as it drifts, and also have easy options for different saved calibration settings (e.g. for 2.2 gamma, 2.4 gamma). And I want to be able to calibrate any new projector I buy, either this year or next year. (I've had to go to great lengths to have my projectors professionally calibrated and it's wearing thin, time to be more self sufficient in that regard).

2. Auto-Calibration. As much as I want to be self sufficient in terms of calibration, I also don't want to become obsessed with it. I'll learn what I need to, but I'm attracted to the auto-calibration features of the software/hardware packages that can be used with the Lumagen (understanding that even with auto-cal, touch-ups are likely needed). Anything to make it more painless and less involved on my part is a good starting point.

3. Cleaner switching in my system. My AV receiver doesn't pass 3D, so I have to use a second long run of cable for 3D out of my oppo to my projector, and switch inputs on the projector to watch 3D, etc. It would be nice to have all 4 of my video sources switching through the same Lumagen unit.

4. Integrated Darbee processing. I have an original Darbee Darblet which I enjoy, except for the fact it's introduced handshake issues, possibly in part because I had to add yet another length of HDMI cable on to my existing 45/50ft hadmi cable runs to my projector. I very much like the idea of getting rid of the extra cabling and also, hopefully, the handshake issues I've been having, by using the Lumagen.

5. I'm intrigued by Lumagen's scaling and processing. This isn't a biggie necessarily, but I still do watch some DVDs. As well, I'm intrigued by trying out the Lumagen 4K scaling on either the Sony 4K projector if I get one (which at least on member here has said works particularly well with Sony's reality creation processing afterward), or with the JVC if I buy one of those. With the Lumagen I could feed the JVC a 4K signal from 1080p, which means it's new MPC processing method will be employed - somewhat different from if it were fed a 1080p signal, and who knows...perhaps an improvement. I'd have to see.

6. Everyone seems to rave about their Lumagen, almost no one seems disappointed. I may find some other features useful that I hadn't even thought about. One, for instance, being able to downsize Blu-Ray menus for navigation to fit my screen when in 2;35:1 mode.

The biggest "con" I see in getting a Lumagen is adding a complicated processor into the mix and it's learning curve. I already use the Denon DVP-602CI video processor. It's pretty user friendly and I use it almost strictly for it's excellent noise reduction feature, which is really amazing at NR without softening HD images. But...people still like that processor so I'm sure I could sell it.
post #1311 of 3991
Quote:
Originally Posted by darinp2 View Post

I haven't tried it with a 4K projector and that may be the case. I'm mostly thinking it through and definitely interested if somebody has better information.

With that 4 pixel misconvergence, if the center is close to perfect after full pixel adjustments there, I figure a zone convergence system needs to transition 4 pixels from the center of the image to the edge. It can do this slowly from whatever zone you start using the sub-pixel convergence capability instead of making sure to only set center zones to full pixel values.

If we think of just the edge of the image where the 4 pixel misconvergence exists it doesn't seem much different to me than 2 pixel misconvergence there, as long as the projector allows the pixels to be adjusted far enough. With either amount of misconvergence you're going to be getting down to less than a pixel of misconvergence there. It is the basic 4 pixels that things have to adjust between the center of the image and the edge versus 2 pixels for the other case that could make a difference, but my gut impression is that this part wouldn't matter a lot as long as it is done smoothly.

That isn't to say that having to use sub-pixel convergence isn't a negative, but once a person is using it I'm not sure having to go 4 pixels over say 2 or 3 feet is much different than having to go 2 pixels over the same distance.

--Darin
In the context of any particular setup swapping a 2K projector for a 4K projector with all else being the same (and if the 4K panel is the same size as the 2K panel) I agree that a 2 pixel misconvergence in the 2K world would be similar to a 4 pixel misconvergence in the 4K world. And I agree that if one cannot see the misconvergence with the 2K setup it's probably going to be difficult to see in a 4K setup. So yes, maybe convergence doesn't have to be more accurate with 4K panel when viewed from this perspective.

That said, this isn't really progress. Sure we have a nice detailed 4K image with the convergence of a 2K projector and it probably still looks super. But from a purest standpoint I don't think that is acceptable. If the 4K panel has twice as many rows of pixels and twice as many columns of pixels in the same physical area as a 2K panel it seems apparent to me that convergence tolerances will have to be twice as stringent in the 4K world to achieve similar misconvergence in the 2K world.

If the algorithms for subpixel manipulation are the same with 4K and 2K panels then I don't think this brings anything new to the table with regards to 4K convergence so what could be done with 4K panels should be doable with 2K panels...electronic convergence manipulation isn't really dependent on pixel count.
post #1312 of 3991
Quote:
Originally Posted by R Harkness View Post

I'm looking at the new Lumagen Radiance 2041, with the 4K outputs. It's been reported here, ok'd by Lumagen, that this unit will be user upgradable to native 4K input for a "modest" fee. So I think I'd be set pretty well if I go for it.

The reasons I'm looking at grabbing a Lumagen are:

1. Calibration. I want to be able to re-calibrate my existing projector as it drifts, and also have easy options for different saved calibration settings (e.g. for 2.2 gamma, 2.4 gamma). And I want to be able to calibrate any new projector I buy, either this year or next year. (I've had to go to great lengths to have my projectors professionally calibrated and it's wearing thin, time to be more self sufficient in that regard).

2. Auto-Calibration. As much as I want to be self sufficient in terms of calibration, I also don't want to become obsessed with it. I'll learn what I need to, but I'm attracted to the auto-calibration features of the software/hardware packages that can be used with the Lumagen (understanding that even with auto-cal, touch-ups are likely needed). Anything to make it more painless and less involved on my part is a good starting point.

3. Cleaner switching in my system. My AV receiver doesn't pass 3D, so I have to use a second long run of cable for 3D out of my oppo to my projector, and switch inputs on the projector to watch 3D, etc. It would be nice to have all 4 of my video sources switching through the same Lumagen unit.

4. Integrated Darbee processing. I have an original Darbee Darblet which I enjoy, except for the fact it's introduced handshake issues, possibly in part because I had to add yet another length of HDMI cable on to my existing 45/50ft hadmi cable runs to my projector. I very much like the idea of getting rid of the extra cabling and also, hopefully, the handshake issues I've been having, by using the Lumagen.

5. I'm intrigued by Lumagen's scaling and processing. This isn't a biggie necessarily, but I still do watch some DVDs. As well, I'm intrigued by trying out the Lumagen 4K scaling on either the Sony 4K projector if I get one (which at least on member here has said works particularly well with Sony's reality creation processing afterward), or with the JVC if I buy one of those. With the Lumagen I could feed the JVC a 4K signal from 1080p, which means it's new MPC processing method will be employed - somewhat different from if it were fed a 1080p signal, and who knows...perhaps an improvement. I'd have to see.

6. Everyone seems to rave about their Lumagen, almost no one seems disappointed. I may find some other features useful that I hadn't even thought about. One, for instance, being able to downsize Blu-Ray menus for navigation to fit my screen when in 2;35:1 mode.

The biggest "con" I see in getting a Lumagen is adding a complicated processor into the mix and it's learning curve. I already use the Denon DVP-602CI video processor. It's pretty user friendly and I use it almost strictly for it's excellent noise reduction feature, which is really amazing at NR without softening HD images. But...people still like that processor so I'm sure I could sell it.
Seems like a well thought out list.
This is the first I've heard of user upgradeability and that takes the sting out of buying now and again later. From my experience using the Lumagen Mini in conjunction with Chromapure you'll need to touch up grayscale and gamma after those are autocal'd. I've not had to do any touch up when auto calibrating gamut.
Edited by Geof - 10/29/13 at 7:05am
post #1313 of 3991
The need for touch up is mostly due to the inability of the D3 meters most are using to be accurate at low end readings. The gray scale will look non gray at around 5% and a touch up will be required. Its not the autocal, its the meters.
Edited by mark haflich - 10/29/13 at 8:24am
post #1314 of 3991
Quote:
Originally Posted by mark haflich View Post

The need for touch up is mostly due to the inability of the C3 meter most are using to be accurate at low end readings. The gray scale will look non gray at around 5% and a touch up will be required. Its not the autocal, its the meters.
Yes, true, but I have also found that even at higher output levels the readings take a bit to settle.....For manual touchups I use the gamma module and when looking at gamma and greyscale in realtime you can observe that greyscale takes a bit of time to stabilize out even below 30%. And with the new JVC lamp I have seen gamma varies quite at higher levels (the lamp output is changing and because gamma is referenced to 100% output if the lamp output changes so does gamma). The effect is that at higher output levels (80-95%) gamma bounces around and the eye does a better job of choosing a value that centers the bouncing above and below the desired set point better than the program. Bottom line for me is Autocal gets it close, it's a useful first step, but it takes manual intervention to fine tune it to achieve best results.
post #1315 of 3991
Quote:
Originally Posted by R Harkness View Post

I'm looking at the new Lumagen Radiance 2041, with the 4K outputs. It's been reported here, ok'd by Lumagen, that this unit will be user upgradable to native 4K input for a "modest" fee. So I think I'd be set pretty well if I go for it.

The reasons I'm looking at grabbing a Lumagen are:

1. Calibration. I want to be able to re-calibrate my existing projector as it drifts, and also have easy options for different saved calibration settings (e.g. for 2.2 gamma, 2.4 gamma). And I want to be able to calibrate any new projector I buy, either this year or next year. (I've had to go to great lengths to have my projectors professionally calibrated and it's wearing thin, time to be more self sufficient in that regard).

2. Auto-Calibration. As much as I want to be self sufficient in terms of calibration, I also don't want to become obsessed with it. I'll learn what I need to, but I'm attracted to the auto-calibration features of the software/hardware packages that can be used with the Lumagen (understanding that even with auto-cal, touch-ups are likely needed). Anything to make it more painless and less involved on my part is a good starting point.

3. Cleaner switching in my system. My AV receiver doesn't pass 3D, so I have to use a second long run of cable for 3D out of my oppo to my projector, and switch inputs on the projector to watch 3D, etc. It would be nice to have all 4 of my video sources switching through the same Lumagen unit.

4. Integrated Darbee processing. I have an original Darbee Darblet which I enjoy, except for the fact it's introduced handshake issues, possibly in part because I had to add yet another length of HDMI cable on to my existing 45/50ft hadmi cable runs to my projector. I very much like the idea of getting rid of the extra cabling and also, hopefully, the handshake issues I've been having, by using the Lumagen.

5. I'm intrigued by Lumagen's scaling and processing. This isn't a biggie necessarily, but I still do watch some DVDs. As well, I'm intrigued by trying out the Lumagen 4K scaling on either the Sony 4K projector if I get one (which at least on member here has said works particularly well with Sony's reality creation processing afterward), or with the JVC if I buy one of those. With the Lumagen I could feed the JVC a 4K signal from 1080p, which means it's new MPC processing method will be employed - somewhat different from if it were fed a 1080p signal, and who knows...perhaps an improvement. I'd have to see.

6. Everyone seems to rave about their Lumagen, almost no one seems disappointed. I may find some other features useful that I hadn't even thought about. One, for instance, being able to downsize Blu-Ray menus for navigation to fit my screen when in 2;35:1 mode.

The biggest "con" I see in getting a Lumagen is adding a complicated processor into the mix and it's learning curve. I already use the Denon DVP-602CI video processor. It's pretty user friendly and I use it almost strictly for it's excellent noise reduction feature, which is really amazing at NR without softening HD images. But...people still like that processor so I'm sure I could sell it.

It will be a trade in upgrade path. The unit its self is not upgradeable.
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post #1316 of 3991
Quote:
Originally Posted by Geof View Post

In the context of any particular setup swapping a 2K projector for a 4K projector with all else being the same (and if the 4K panel is the same size as the 2K panel) I agree that a 2 pixel misconvergence in the 2K world would be similar to a 4 pixel misconvergence in the 4K world.
They should be similar, but the 4K has an advantage if using the zone convergence. If the misconvergence is exactly 2 pixels in the 2K world then it can be fixed with full pixel shifts, but if it is 1.5 or 2.5 then the same amount (3 or 5) can be fixed completely for that spot in the 4K world as long as the projector has enough shift range. The transitions between the center and the edge of the screen can be smoother with the 4K with the same viewing ratio too.
Quote:
Originally Posted by Geof View Post

That said, this isn't really progress. Sure we have a nice detailed 4K image with the convergence of a 2K projector and it probably still looks super.
If you need the zone convergence with both then the 2K projector has the convergence of a 1K projector by that logic, so seems like progress.
Quote:
Originally Posted by Geof View Post

But from a purest standpoint I don't think that is acceptable. If the 4K panel has twice as many rows of pixels and twice as many columns of pixels in the same physical area as a 2K panel it seems apparent to me that convergence tolerances will have to be twice as stringent in the 4K world to achieve similar misconvergence in the 2K world.

If the algorithms for subpixel manipulation are the same with 4K and 2K panels then I don't think this brings anything new to the table with regards to 4K convergence so what could be done with 4K panels should be doable with 2K panels...electronic convergence manipulation isn't really dependent on pixel count.
Would you say the same between 32K and 2K for example? Would the convergence tolerances need to be 16 times as stringent even if they supported full zone convergence?

Let's try using degrees of vision instead of pixels since the pixel sizes change. I'll use some rounded figures for simplicity. If we assume somebody sits so that the image takes up 32 degrees of their vision then we have the following average for degrees of vision per pixel in the horizontal direction:

1K: 0.032
2K: 0.016
4K: 0.008
8K: 0.004
16K: 0.002
32K: 0.001

With the 2K model the convergence for a single spot can be within 0.008 degrees without using any sub-pixel adjustments. With the 32K model that is 0.0005 degrees with no sub-pixle adjustments. And if sub-pixel adjustments are used then on the 2K model it needs to account for misconvergences of 0 degrees to 0.008 degrees after full pixel shifts, while on the 32K it only needs to account for misconvergences of 0 degrees to 0.0005 degrees after full pixel shifts.

If we apply that to a case where the center is perfect and the edge of the image is off by 1.5 pixels in 2K space (24 pixels in 32K space), in the 2K case the edge will have sub-pixel adjustments to fix that half a pixel and then a transition needs to happen between the center of the image and the edge that will go a whole pixel plus another half. So, some places in between the center and the edge will be 0 pixels (0 degrees) off and some will be half a pixel off (0.008 degrees, but fixed with 2 pixels). With the 32K projector the center and the edge will be perfect, but then the transition between the center and the edge needs to account for 24 pixels. This is a lot of transitions, but should be able to be done smoothly because each spot will only be off by 0.5 pixels in 32K space at most (1/32nd of a pixel in 2K space), or 0.0005 degrees at most.

I don't know the algorithms they use (any shortcuts taken especially), but as long as they give enough adjustment range (so need more range in pixels counts as resolution is raised) it looks to me like they should be able to get better convergence at the higher resolutions for the same viewing ratio.

If somebody knows of a reason that having to move 24 pixels over a range of say 10,000 in my 32K example above would be a problem please say something. If I messed up any of the math that would be good to know too.

--Darin
post #1317 of 3991
Quote:
Originally Posted by darinp2 View Post

They should be similar, but the 4K has an advantage if using the zone convergence. If the misconvergence is exactly 2 pixels in the 2K world then it can be fixed with full pixel shifts, but if it is 1.5 or 2.5 then the same amount (3 or 5) can be fixed completely for that spot in the 4K world as long as the projector has enough shift range. The transitions between the center and the edge of the screen can be smoother with the 4K with the same viewing ratio too.

If by zone convergence you're referring to adjusting convergence in 1 pixel increments (regardless of how many pixels there are) then yes, I agree with you.

I guess where we differ on the rest is you make valid points about the degree of the error as resolution increases whereas I would prefer to see the error not increase as pixel count increasers. IOW, if the convergence spec is 1 pixel tolerance for 2K then I would prefer it to be 1 pixel tolerance with 4K as well. Your argument basically says if a 1 pixel error is okay in 2K then a 2 pixel error is similar in 4K (and similarily 16 pixel errors would be similar in a 32K setup). If screen size and viewing distance don't change between a 2K and 4K setup then you're right and I'm sure that is how it'll be. But personally I think this is the wrong approach and I would prefer to see convergence tolerances tightened up with 4K projectors.
post #1318 of 3991
I think its zone vs global. The shift whether in full or subpixels has nothing to do with global vs zone. Global means moving the image produced by Red, Green, or Blue pixels. the same amount across the entire image. Thus moving everything up or down 2 pixels and horizontally left or right 2.2 pixels would be a global adjustment. Zone or zonal would mean dividing the image up into some number of blocks and doing the adjustments just with that block. Zonal is useful for dealing primarily with chromatic aberration rather than misconvergence I would think.
post #1319 of 3991
Quote:
Originally Posted by Geof View Post

If by zone convergence you're referring to adjusting convergence in 1 pixel increments (regardless of how many pixels there are) then yes, I agree with you.
I was referring to the sub-pixel adjustments some of these projectors have where you can adjust the center by whole pixel increments (so off by half pixel max there) and then adjust the zones near the edges to different amounts. Even if you used only whole increments there, if you used different increments than the center of the screen the projector would still need to do sub-pixel adjustments between that point and the center of the image.
Quote:
Originally Posted by Geof View Post

Your argument basically says if a 1 pixel error is okay in 2K then a 2 pixel error is similar in 4K (and similarily 16 pixel errors would be similar in a 32K setup).
I wouldn't say that was exactly the position I was taking unless you don't count the ability to then fix that error. I was taking the position that the higher resolution projector has more capability to fix up that misconvergence with the zone and sub-pixel adjustments. So, the final result should be better with the higher resolution if that feature is used in both cases.

In other words, I'm not saying leaving the 32K projector off by 16 pixels is a good thing. I'm saying that it can be adjusted down to .5 pixels or less for every spot over the whole screen (even not giving extra credit for 2 pixels looking like less misconvergence for that one point) where the 2K projector cannot always be adjusted down to 1/32nd of its pixel or less (in fact in most cases it cannot).

--Darin
Edited by darinp2 - 10/29/13 at 12:07pm
post #1320 of 3991
Here's an issue I'm wondering about concerning calibration of the JVC projectors: Calibrating for 3D.

My projector had been calibrated only for 2D, but now I'm checking out occasional 3D. It's just barely bright enough as it is, but also the calibration is clearly not very accurate in the JVC's default 3D mode. Basically it just defaults to a high-bulb, dynamic type picture mode. Which is understandable given that's a way to give the 3D image as much light out of the projector as possible. But then, if one wants a more color-accurate, calibrated 3D setting, the issue is accurate calibration always drops the light output, often quite significantly, from any dynamic modes. So am I wrong in presuming that accurately calibrating for 3D is going to have the trade off of an even dimmer image for 3D? (In which case...it's almost why bother?). Or have some people done some sort of compromise calibrations for 3D on their JVCs that gets decent light output and "good enough" color for 3D?
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