My question is, if you have an LCoS projector (JVC RS1/RS2 or any of the Sony VW series) can this problem with bright or miscolored corners show up or develop later in the projectors' life or is this something that you'd notice upfront and is unfixable besides returning the unit?

Thanks for any and all feedback.

Anyone know or have experience with this?

Much appreciated.

I haven't noticed any issues on my VW40. I don't have enough familiarity with LCOS to say if it can show up later, but I sure don't see it now.

I believe it's a birth defect; I've never seen anyone say it appears later.

I don't see bright corners on my RS1 now. When I first got mine I could see it slightly but I needed to sit in the dark for a minute or two to see it. Now after 150 hours they are gone. I don't have any major color uniformity issues either. All 10 IRE levels on video essentials look the same by eye to me. Nice white or grey fields.

I see, thanks a lot for the info. So it seems, if you receive one with no problems and that has been QC'd then you should be good-to-go as far as this issue.

Yeah I have never seen a uniformity issue suddenly appear.

My HD-1(RS-1) have a green discoloration at the bottom left corner of the screen. It was not there previously when I bought it new. The lamp hour is at 225 now and I wonder if it is the lamp that is causing it..

My question is, if you have an LCoS projector (JVC RS1/RS2 or any of the Sony VW series) can this problem with bright or miscolored corners show up or develop later in the projectors' life or is this something that you'd notice upfront and is unfixable besides returning the unit?

Thanks for any and all feedback.

First, to clarify, there are really two different issues being discussed here. The first is "bright" corners. The second is "discolored" corners.

You can find threads around here dealing with both issues, but the bottom line is that these are caused by different things. The problems causing bright corners are not likely to change over time, but they also tend to appear to varying degrees on most of the LCOS projectors I've seen, although my experience tells me that most owners do not find the bright corners to be noticeable in most content and generally say that it's not very objectionable.

Discolored corners is a different deal. First off, discoloration of LCOS panels is not restricted to corners, but rather can appear anywhere on the screen. First and second generation Sony SXRD rear-projection sets had a big problem with the "green glob," a large blob of green discoloration. The discoloration on LCOS displays will show up as shades of green and/or pink, depending upon the 3D gamma settings as well as the ability of those settings to correct said discolorations.

And yes, discoloration can and does drift over time, at least on some projectors (I'm not saying all). I'm not sure why, but I do have to adjust my 3D gamma tables every now and then, and honestly some of the more subtle discolorations are beyond repair. But honestly, most people would never notice the issues that I've had, since they are very subtle.

However, much of this is owed to correct setting of the 3D gamma tables at the factory before the projector is shipped. And I noticed that the settings were different for inverted versus table mount. Discoloration on my projector was beyond terrible when it was table mounted, but was pretty darned good once I flipped it upside down.

Nice post Gremmy!

First, to clarify, there are really two different issues being discussed here. The first is "bright" corners. The second is "discolored" corners.

You can find threads around here dealing with both issues, but the bottom line is that these are caused by different things. The problems causing bright corners are not likely to change over time, but they also tend to appear to varying degrees on most of the LCOS projectors I've seen, although my experience tells me that most owners do not find the bright corners to be noticeable in most content and generally say that it's not very objectionable.

Discolored corners is a different deal. First off, discoloration of LCOS panels is not restricted to corners, but rather can appear anywhere on the screen. First and second generation Sony SXRD rear-projection sets had a big problem with the "green glob," a large blob of green discoloration. The discoloration on LCOS displays will show up as shades of green and/or pink, depending upon the 3D gamma settings as well as the ability of those settings to correct said discolorations.

And yes, discoloration can and does drift over time, at least on some projectors (I'm not saying all). I'm not sure why, but I do have to adjust my 3D gamma tables every now and then, and honestly some of the more subtle discolorations are beyond repair. But honestly, most people would never notice the issues that I've had, since they are very subtle.

However, much of this is owed to correct setting of the 3D gamma tables at the factory before the projector is shipped. And I noticed that the settings were different for inverted versus table mount. Discoloration on my projector was beyond terrible when it was table mounted, but was pretty darned good once I flipped it upside down.


How do I set the 3D gamma table on a RS-1? I guessed i need an external video processor?

How do I set the 3D gamma table on a RS-1? I guessed i need an external video processor?

You can't AFAIK. It was possible using specialist software tools and expertise (Wm Phelps) with ealier analogue D-ILA displays to adjust panel shading. With the change to a digital driver on the HD1/RS1/HD100/RS2 this isn't possible currently. AFAIK no consumer level VP provides this type of feature either.

D

You can't AFAIK. It was possible using specialist software tools and expertise (Wm Phelps) with ealier analogue D-ILA displays to adjust panel shading. With the change to a digital driver on the HD1/RS1/HD100/RS2 this isn't possible currently. AFAIK no consumer level VP provides this type of feature either.

D

Thanks for the advise. Hopefully something is available in the future for panel shading adjustment..
I wonder what caused shading since my JVC RS-1 panels are pretty well converged

Thanks for the advise. Hopefully something is available in the future for panel shading adjustment..
I wonder what caused shading since my JVC RS-1 panels are pretty well converged

I think it's an inherent feature of LCOS due to current manufacturing limitations. I've noticed colour tininting on the righthand outer screen area using full field grayscale patterns. This does appear to be caused by slight red CA/MC in those areas. I guess that's different to the cloud/band type shading that can appears on the same patterns. I don't think one is releated to other.

D

My Black Pearl, which has been basically flawless since I installed it with a ceiling mount, hasn't had a moment of either discoloration or brightness in the corners.

Before the picture comes on, in the warm-up period, the upper left corner looks a little brighter than the rest of the screen, but when the picture finally clicks on, I see no difference.

It's just great having a 120" diagonal screen and getting such a picture. Now my screen is gray, and I do have a lot of ambient light, so I can't say what it all might look like in a totally dark, white screen setting.

Just as to my setup- a vw60 (purchased from AVS), a gray screen and too much light filtering in, I have no issues with - well with anything. I have been doing this home theater thing since last November, so compared to a lot of folks I'm a rookie, but the information I got from this site has been excellent, the product I got from them was exactly as advertised and the performace of it exceeded my expectations.

I'm sure there are variations in units. We hear about it. You won't hear about it from me, though. No bright or discolored corners here.

Would such discoloration be considered grounds for replacement under warranty?

Would such discoloration be considered grounds for replacement under warranty?

I guess it depends on the severity. I know there is a class action against Sony re similar issues with some of their SXRD rear projection TV's.

D

My guess is that much of the bright corners / general uniformity problems are due to a lack of proper setup/QC in manufacturing. The Sony Pearl series (40/50/60) all have extensive 3d gamma settings in the service menu. It appears that these settings are different per projector from the factory. This leads me to believe that 1) there is some process to help the uniformity issues at manufacturing time and 2) that process is inadequate in that it does not remove all visible shading. I have "bright" corners in the upper left and lower right on my VW60. I have heard at least one other poster mention this same pattern (upper left + lower right). This leads me to believe that the factory shading adjustment is "off" / not perfect. Also the fact that there are/were 3rd party DILA shading adjustments that reportedly made significant improvements to the image quality is another indication to me that it is an area that could be easily improved on in manufacturing if the manufacturers decided it was important. I assume that they don't do it due to a lack of demand coupled with the cost of tooling up the shading quality equipment/process and the amount of time it would add to each unit for manufacturing.

I had bright corners that went away on my Pearl (even after new bulbs). So far the bright corners on my VW60 have not appeared to fade. On the Pearl, other uniformity issues became worse over time. The VW60 does not have any visible uniformity issues other then the slight elevated corners.

I have "bright" corners in the upper left and lower right on my VW60. I have heard at least one other poster mention this same pattern (upper left + lower right). This leads me to believe that the factory shading adjustment is "off" / not perfect.


I'm not saying you're wrong regarding your projector (and maybe others), but I think generally speaking that the bright corners issue is not related to shading. WPhelps at one point said that he had no cure for bright corners, even though he was apparently capable of calibrating the Sony projectors to have nearly perfect shading.

There has been a lot of discussion that the bright corners is related more to light engine design. Personally, I'm not 100% sure, so I won't pretend to be. And in support of your point, I can imagine a scenario by which shading errors could appear as "brighter" or "darker" areas of the screen in very low APLs (as opposed to pinkish or greenish areas of the screen), because when the image is very dark, brightness differences might be more apparent than color differences.

But I never hear anyone complaining about a bright mid-screen, or a bright blob. It's always bright corners. If the bright corners are truly related to shading, I would expect the bright areas to come in every shape and size, as the pink/green shading discolorations do indeed come in every shape and size.

The bright corners may very well be a "hardware" issue rather than a shading one. Given that at least two DILA/SXRD manufacturers (Sony and JVC) have significant reports of bright corners, that might point to a general design issue in the light paths. Perhaps there is some common element in the light path designs that causes this. The other possibility is that the corners are shading issues, and there is a flaw in the shading correction equipment that does not correct those corners for some reason. Granted that possibility seems less likely than a hardware issue to me, but who knows?

On the VW60, I can't tell if the elevated corners are "colored" or "white", not enough light output at full black to see or for me to measure with my colormeter.

My VW50 had a subtle "bullseye" (concentric rings) like reg/green uniformity pattern across the entire screen, I can only attribute that to inadequate factory shading correction.

As said previously, it is a well documented fact that vw series (at least vw60 that I know of) has slightly brighter top left and bottom right corners. This is really negligible and you would see it only if you look for it in a fully dark seen or when the screen is black. I have seen many LCD panels with worse brightness uniformity issues.

IMO, this is not an easily fixable problem and it is related to some design issue, probably the light engine as someone mentioned. If it is easily fixable, Sony should have fixed this issue, in new units, by now.

I just noticed my Epson LCD projector has a brighter bottom-right corner. I'm still in my return window, should I try to exchange it, or are these bright corner issues usually a flaw in design that is pretty much present on every unit of identical model PJs?

I just noticed my Epson LCD projector has a brighter bottom-right corner. I'm still in my return window, should I try to exchange it, or are these bright corner issues usually a flaw in design that is pretty much present on every unit of identical model PJs?

The Epson is LCD, this is a LCOS thread...If you were to ask that in the thread for you exact model I think you would have better luck.

I just noticed my Epson LCD projector has a brighter bottom-right corner. I'm still in my return window, should I try to exchange it, or are these bright corner issues usually a flaw in design that is pretty much present on every unit of identical model PJs?

Depending on how bad it is, you may get a worse/similar/better unit if exchanged. Remember on this basic technology there are some limitations for performance (no perfect one). Sort of "exchange at your own risk" type scenario.