Prism contamination

[Mike Blakesley]

We're looking at replacing our 9-year old screening room machine and if the prism or equally expensive item would die today, I wouldn't spend the $5K to $15K to replace it with a refurbished or new one. Still, it's your business and therefore your bet on what's the wisest decision going forward.

My biggest problem is I want to get a new projector! Especially knowing we need to replace it soon anyway has me leaning that way. Our tech did indeed say the problem would get worse, but he also said since we normally only have one show a day it wasn't going to happen overnight.

How intrusive is it on normal content? Are you able to spot it?

I don't think a typical audience member would notice it, unless it was in a picture that was obviously supposed to be all-white. Although, we're showing Guardians of the Galaxy 3 and there are some light colored scenes right now and it looks awful (to me). But nobody has said anything. I hate that this is happening at the beginning of summer!

Luckily we're showing "Little Mermaid" starting Friday which (going by the trailer, at least) is mostly all in various shades of blue, so problem solved...for 3 weeks at least.

[Dave Macaulay]

We had an exchange prism for an NC2000. The problem was very visible looking into the prism face lit from the front but moreso with a phone flashlight from the rear.
The exchange one was fine, all image discoloring gone.
The prism came clamped in a cage, just the prism. It's not a trivial job to take one out of the projector's prism mount and worse to put one back in. The wiring, cooling plates, hoses, thermistors, etc have to be put on exactly right.

[Marcel Birgelen]

Discolorations like this are indeed likely due to prism issues. It could be some dirt, but also a problem with the bonding of the individual parts of the prism. How intrusive is it on normal content? Are you able to spot it? One problem may be that, if the prism is disintegrating, the problem will probably get worse over time, a lot like a windshield that has been cracked.

Jason's fix will reduce the impact for scope, but will not fix your issue for flat. It also requires you to realign the projector towards your screen. If you only plan to run scope content for the foreseeable future, it's probably a good, temporary fix.

If you have the budget for a new machine, I don't think I would spend prism-replacement-money to fix this 15-year-old machine. We're looking at replacing our 9-year old screening room machine and if the prism or equally expensive item would die today, I wouldn't spend the $5K to $15K to replace it with a refurbished or new one. Still, it's your business and therefore your bet on what's the wisest decision going forward.

[Jason Sharp]

Strong offers a prism exchange program. Probably $4k or $5k plus the technician fees. As a temporary fix you could program the scope macro on your NEC to use the bottom 858 pixels of the DLP chip to minimize the amount of blue on screen until you repair/replace.

[Mike Blakesley]

I was thinking the picture from our NEC NC2000 projector was seeming a little dim, so I decided to check the bulb alignment. Afterward I ran a white-screen test pattern and noticed the top right hand corner of the image has a definite blue tint to it. It looks like somebody accidentally lightly sprayed the area with a sky-blue spray paint.

screen.jpg

Our technician diagnosed "prism contamination" which sounds expensive. The good news, he says, is death isn't imminent and we have a few options on what to do, including installing a refurbished light engine. I was already gearing up for replacing the projector anyway since it will be 15 years old next year. I'm torn between going ahead with the fix (with the knowledge that some other expensive thing could happen 6 months from now) or biting the bullet for a new machine.

I love show biz!