color uniformity problem

No, it's definitely not a lamp issue. What make/model do you have?

Nope, that will not be a lamp issue. There is no way the lamp can give you uneven color. Why? Because for one thing, the light is unfocused at that point. Only when it goes through the optics is it directed and focused and MIXED. Second, the lamp is not capable of producing different shades of color across the field. It puts out uniform light.

The projector has a problem.

Hi Kiwi. You did not say what brand & model is your PJ. LCD or DLP? Could you post a picture of the problem? On a white field, do you see the screen reddish on one side and bluish on the other? LCD: bad convergence, burned or dirty polarizers could cause this. I do not think this is a lamp problem, but, depending of the PJ and the use (1600 on high? to many on-off cycles? etc.), it coud be very dim by now, and now you are seeing more the problem than before when it was very bright.
Fernando

I had a similar problem develop towards the end of the life of an Infocus SP5000 (LCD).

I also see the same issue on a brand new Mitsubishi HC3800 (DLP) I unboxed last week.

Based on anecdotal evidence, I gather the issue is somewhat widespread on the HC3800s.

What make and model again? Lamp assembly could mean a lot of things.

Generally with LCD this is can be a polarizer issue, the polarizers could be in what could be called the "lamp assembly" I suppose. Depending on actual design.

Who's the manufacturer? That sounds like BS to me. It's a problem with the optical block, but it sounds like they're pushing you to buy a new lamp.

You would be correct, it is widespread on the 3800s. And, according to Mitsubishi's Engineering Manager at the CA repair facility, "It is not a malfunction, but completely normal with that model line."

However, on the 3800, it seems to get better (clear up a bit) with time on the bulb rather than worse.

Search the 3800 thread and you will see pics and several posts about this.

Its a very common problem with all LCDs. In fact I suspect that almost all of them suffer from the problem. Fortunately it only really shows up grossly in B&W movies and when you try to calibrate the machine.

I will not buy an LCD again because of this problem.

Well, they are saying over on the Mitsubishi HC3800 DLP projector thread that the 3800's color uniformity issue IS from the bulb and that with time on the bulb (200+ hours) the problem will fade for the most part. AND, I have seen this for myself. My 3800, which is DLP and NOT LCD, arrived with really bad color uniformity with the screen looking reddish to white to bluish across the screen. After about 200 hours on the thing, though, it had faded away greatly. Guys over there on that thread who have seen this on their own DLPs have said that color uniformity on DLPs often settles or fades with time on the lamp.

Did you know that it has been estimated that over 95% off information on the web is incorrect? Of course, that estimate was found on the web.

Consider that in a DLP projector, the light from the lamp must pass through the color wheel and then a light tunnel before it enters the imaging chamber. It is not possible for any variation in color uniformity to pass though unaffected. The light is bounced around inside the tight tunnel as it passes through. Any variations (however unlikely) are evened out across the image field.

In an LCD projector, there is a diffuser immediately after the lamp, then the light passes through multiple splitters to separate the light into 3 paths, then bounces about with some mirrors, then the light is directed through polarizers, then the LCD panels and finally into the prism, where all three light paths are recombined and directed out the lens.

I understand that other people have reported this issue, I just don't see how it's possible.

You're correct, I missed that part. However, someone DID mention DLP projectors in this thread. However, I did edit my reply to properly address your question.

But my opinion remains unchanged. As I said, I don't see how it's possible in EITHER technology because of the optical path designs in each.

+1.
LCD non uniformity causes (my take):
Bad convergence and/or
burned polarizers and/or
dirty internal optics/polarizers/LCDs.

My Panny ae700 developed this issue overnight after about 3 years of use, the screen was became red on one side and blue on the oher. Believe it or not I was able to correct the problem by going into the service menu and selecting the option that allows you to cycle manually through different solid colours. I did this for about 5-10 minutes, and the problem improved drastically. Did it again and the problem went away. I posted this solution a year or so back and it seemed to solve the problem for somebody else too. Give it a try, it won't cost you anything

That suggests a degradation problem with the panels. If that's the case and the projector does not have that cycle feature, you can try a trick used by videographers back in the days before digital imaging when they had a burned image. And that was to open the iris all the way focus on a pure white image for a period of time. What you would do is to project nothing but pure white for a several minutes of an hour and see if that doesn't clear it.

In that case you might want to try the stuck pixel fix. It flashes your screen multiple times in rapid succession. Perhaps it will also fix the sudden color change you are seeing.

http://www.youtube.com/watch?v=VaTTj...eature=related

Well, so much for trying to help. You're welcome.

You assume it will be fixed.....

kiwi, I'm sorry to say, but this is typical of Sanyo. Many people had three year warranties on the Z series of projectors and everytime something went wrong they received a standard response saying it was either the customers fault(they would claim the customer didn't change the filter even though it was clean) or they would say it was normal wear.

How in the world can it be normal wear with only 1600 hours on the darn thing? though I was lucky when I had a Sanyo(2 yrs ago), I'll never buy another one due to all the stories that are just like yours here on AVS.

Don't take this BS from them. Go higher in the service chain and speak to a manager and if that doesn't work take it even higher and tell them you're going to take it higher and use their name too.

If you take it higher after the service manager contact:

Mark Holt
Vice President
(757) 564-8070 (Voice)
(818) 693-6923 (Mobile)
(757) 564-6826 (Fax)
mholt @ sfc.sanyo (dot) com

That last statement from Sanyo can be misleading and misinterpreted. While it is true that a lamp will experience a color shift as it ages, the change is very gradual and very small, not dramatic. But here is the important part, the color shift change is uniform across the entire image. What you described early in this thread is impossible for a lamp to produce.

Think about it, one side of the image goes red...that's warmer. The other side goes blue...that's colder. While the center stays white? No, Even if it were possible for the lamp to create different shades in different parts of the image, it would have to get hotter on one side and cooler on the other side. Just not possible.

And this is all beating a dead horse for you,I know, but I took this opportunity to make this point for the other people that come in and read this thread.

Sanyo's report pretty much confirmed what we were saying, not that we take pleasure in it. And it is unfortunate that they take this stance on "acceptable image quality". It doesn't speak well for their support and customer care.

News like that is never good and we all "feel your pain" and sympathize. The good news is that the projector is still usable and can continue to perform for you until it fails, provided that the color purity issue is not objectionable. Or you could be the type of person who will be looking for it very time you watch it and let yourself be driven crazy.

It can't and I didn't have the understanding that the problem was that bad. Sorry.

But for what it's worth, I don't think that any of the tips that were offered here would have helped that problem if the panels are degrading or the polarizers are burned.