One of my projectors is projecting an odd distortion?

[Nathan Paris]

Hello everyone!

My theaters use Christie Series 2 CP2220s.

Recently I noticed on one our screens that we're seeing a strange "wrinkling" in the bottom left corner of our projector when it's playing something. Does anyone have any idea what it could be and potential fixes?

I've displayed a test pattern and tried zooming in and out and the distortion moves with the zoom level, so I know it isn't an issue with our physical screen. We checked the window for cobwebs, dust, etc. but that hasn't fixed anything either. Lastly, I swapped bulbs to see if there was a bulb issue but the problem persisted.

Before I take any drastic measures of replacing the projector entirely or taking it down for weeks while we get a technician out here I wanted to see if anyone has seen anything like this in the past, if there's a way to fix it, and what could have caused it to prevent it from happening in the future.

[Leo Enticknap]

The vertical ripples descending from the top look to me like a screen tension issue. The artifact bottom left looks like some hairs have gotten into the optical path somewhere. Others here are way more knowledgeable than I about Christies, but my suggestion would be to follow the optical path from the front of the lamphouse to the light engine compartment, to see if you can find it. If it's actually on the prism, cleaning it off could be a significant problem. Worth removing the lens and checking the area between the lens holder and the dowser, too.

[Caleb Williams]

See if you can isolate the trouble to a specific color first, since no dissassembly is required for that. If it only shows up on one of the three colors then it is likely that something has landed in the small gap between the prism and the DMD chip of the effected color.

If all colors are effected, then work your way from the front to the back of the projector.

1) Inspect the lens for any signs of damage, both internal and external. You should be able to see if something has come loose or if a lens element has cracked by shining a flashlight into the front of it and seeing what you see.

2) If the lens is okay, the next easiest place to check for debris is between the lens and the front of the prism. Pull the lens from the front of the projector, and check the back of the lens for contamination, then inspect the prism for the same. If nothing obvious is found, move on

3) The prism in the 2220 is compound with several parts either bonded together, or left with a tiny gap between elements. On the front of the light engine there is a unifying prism that is separated from the larger glass section by less than a millimeter. Occasionally a small spec of dust may end up in this space and occlude the image. This area should be cleaned by a qualified Christie technician if needed. Although it is possible that a small non-oily contaminate could be removed with light puffs of air. DO NOT USE COMPRESSED ELECTRONIC AIR DUSTER CANS. They have bitterant that can dirty the light engine elements.

4) The light engine sits above a UV filter and the fold mirror. I have seen small bugs make their way into this space and occlude the image in very interesting ways. To clean this space the light engine must be removed by a certified technician.

5) The integrator rod is the next piece back. It is only easy to visually inspect the end inside the lamp house, but if you look directly down the length of the integrator rod is should look as though the glass is nearly invisible, like you're looking through a hollow square tube. I have seen integrator rods chip due to exposure to heat, and they have caused, albeit much smaller, similar effects to what you have on screen. The integrator rod should be replaced by a certified tech.

6) aside from the lamp, the reflector is the last piece of the puzzle. Make sure there are no foreign objects on/in the reflector


Because the aberration moves with lens adjustments, it has to be at some point in the light path. Aside from the things listed, it is possible something catastrophic has happened to your light engine, but unlikely. Check the easy stuff first, and you're sure to spot the issue.

Also, I'm with Leo on the top folds in the screen.

[Randy Stankey]

That distortion in the corner looks like a shatter cone.

(i.e., some piece of glass in the optical path took some shock and cracked the glass but didn't fully dislodge the broken chip.)

[Josh Jones]

Cracked integrator rod would be my guess.

[James Gardiner]

Cracked integrator rod would be my guess.

The cracked ROD would be in such good focus. I would guess its in the light engine close to the DMD or optics towards the end of the light path just before the lens..

[Ioannis Syrogiannis]

Cracked integrator rod would be my guess.

If memory serves right, that's what a chipped integration rod looks like.

Indeed, the screen needs some attention.
ChippedR.jpg

[Steve Guttag]

I don't think the light rod because when they get even chips, you get rainbow colors around blemish.

If you put up the three primary colors, one at at time, are the distortions there? My guess is yes. If so, it has to be something that affects all three colors so entrance/exit of the light pipe, fold mirror, exit of the prism, the lens, the port. Possibly the yellow notch filter.

[Marco Giustini]

@Nathan
As others said, looks like some cracked optical element in the way.

That said, you're thinking of swapping the projector for that but you're not considering re-tensioning the screen???

[Randy Stankey]

That said, you're thinking of swapping the projector for that but you're not considering re-tensioning the screen???

Pre-qualification, here... I know what it is like when there is an issue that management will give neither time nor money to fix. When I say "you" I don't mean "Nathan." I mean "You, the management." So, with that out of the way...

Why are "you" whining about artifacts on the screen, due to a damaged projector, when you have a screen that looks like a flag, waving in the wind? I think you are being weirdly selective about what things to fix!

Fix the screen! NOW! It will only take a few hours of overtime, after the last show of the day. You will only need a couple of guys, a ladder and some hand tools. Half of your problems would be solved, virtually overnight, with comparatively little expense, relative to the THOUSANDS it will take to fix the projector. If I had to choose between the lesser or two evils, I'd rather see a "splotch" in the picture than watch a movie on a screen that looks like a bed sheet, hanging on a clothes line!

If you are willing to let your PAYING CUSTOMERS watch a movie on THAT screen, why are you even worried about a broken projector, at all? If I was a customer in your theater, I'd be walking out, demanding a refund before the ads and trailers were even finished playing!

Hey! Manager! You are killing your own business then whining because you don't have enough money to fix your projector!

Rectal-Cranial Inversion.jpg

[Adrian Avram]

I am pretty sure that is a chipped corner on the integrator rod, the side that is toward the Light Engine (front of the projector). In a pinch you could open carefully the integrator and rotate the glass rod that is inside with the chipped corner toward the lamp and it should be fine.

[Randy Stankey]

It is true that a lens or optical component can't resolve a foreign object on its own surface but that doesn't mean it can't block the light. You will hide the damaged part but much of the light in that area is blocked or scattered, leaving the possibility of a dark, blurry spot.

Sure, it'll work but you're still going to have to get it repaired the right way. This should only be considered a temporary measure, at best. It'll be enough to get you through but don't count on it as a permanent fix.

I don't know how many times in my life I've done things that were "just temporary" that ended up becoming permanent. Then, later on, when something really goes wrong, you look back and ask yourself. "Why didn't I get it fixed when I had the chance?"