CHRISTIE CP2215 pixel shift

[Christopher Mondt]

Hello

We have the following problem on a CHRISTIE CP2215.

On all images the pixels are regularly shifting by on pixel.

Attached I send a short video of the problem.

Meaning the pixels are alternating by one pixel.
This happens in both direction, horizontally and vertically.

You can see it, the best on the grid test patter with lines.
This happens permanently with a regular frequency of about 0.5 second.

It seems it was already there from the beginnig of the installation of the projector.


We did the following so far:

- Checking if it is a vibration in the projector:
Everything is fixed.
No vibrations of fans
It is an electronic issue.

- We have swapped the ICP and the PIB and it stays the same.


Did anyone discover this effect before?

Should we swap the lightenegine?


Thanks for any ideas.


Christopher

[Marcel Birgelen]

To me, this looks like some temporal dithering going on... Are you, by any chance, scaling the image?

[Christopher Mondt]

No scaling, No nothimg.

Even after factory reset the same on all test patterns and on all content

Strange isn't it?
Loose panel ?

What can it be?

[Ioannis Syrogiannis]

Whatever it is, it doesn't seem to be convergence related. The colors that could have been a bit better converged seem stable.
Just curious, is this test pattern screening from the ICP/projector, or playing out of the server?
Also, do you have any non-alternating checkboard test pattern on the projector? Does it seem O.K. (apart from the slight convergence offset)?

[Christopher Mondt]

Testpattern is original CHRISTIE from ICP.

[Steve Guttag]

It looks mechanical to me. I would use a different test pattern or a collection of them. If you use a crosshatch with just one primary color and then switch between them, do they all do the same thing? My guess is yes. You can also load a Barco test pattern for convergence (DP2K-C) as well as the framing uncorrected. Look at where the three primaries line up with each other. Do they move with each other or does one color move on its own. If they move together, it is definitely mechanical (vibration). The three formatters are independent. You've already changed the ICP and that is the only place where the image has any commonality and I've never heard/seen this problem.

If possible, move the projector to another screen (swap), ideally with the same lens EF so it all moves. Does the problem move. If you don't have a place to move it to, try just shooting it in another room (doesn't have to be a theatre) and see if the problem remains in the same spot of the image.

[Mark Gulbrandsen]

A loose lens element , or a loose group of elements inside could definitely cause this problem. Had it happen once when the spinning wheel on a Master Image 3-D adapter exploded and a large chunk of it hit the lens.The projector was found to be fine when I moved a lens from an adjoining room to replace the dented lens.

[Ryan Gallagher]

A little hard to tell from the video, but I 2nd the suggestion of checking the different colors individually with a host of test patterns. If they are all doing it together, optical or mechanical seems most likely? It could be one of those weird thermal gradients in the auditorium air... do you notice it over the entire image or is it more pronounced in certain areas? Does the white field viewed from a distance look to have any caustic distortion patterns flowing across it etc?

Try it with the air handlers both on and off in the auditorium, and test both heating mode and cooling modes too. Closer to the booth (or within the booth), are there any air handlers blowing very near the lens or the port glass to try blocking or disabling? That might have been where Steve was headed with his thought to try swapping that projector to a different auditorium?

[Marco Giustini]

ONE second of video? Helpful!

I second Steve, this seems mechanical. Something is vibrating somewhere. Decouple the extract fan from the top of the projector, make sure the lens is firmly attached. Switch other heavy machinery off to stop vibrations as a test.

[Marcel Birgelen]

Since it's so hard to see what's actually happening here, why not zoom in the projector to the maximum achievable, focus in on it as sharply as possible, push the lamp to 100%. If you have a large piece of white paper, have someone hold it against the screen. Then, film again, but this time a bit longer please, also to see if there is a cycle in the pattern.

I'm not convinced we see a pure pixel shift, but it's rather hard to judge whether this is an electronically triggered issue or a mechanical/vibration issue.

[Christopher Mondt]

Thanks guys.

On Wednesday we have a whole day in the cinema to check everything again.

I will also try with different lens.

and will try to make better videos.

The effect is evenly over th ewhole picture.

[Hong Sung Hyeok]

I suspect the lamp fan. It doesn't seem to vibrate, but it could be.
The CP2215 has a small, short lens, so it's unlikely to cause vibration. However, if you gently lift the bottom of the lens with your finger, you can check if the image on the screen vibrates.

If you suspect it's from the time of installation, check the basics. Are all the projector feet evenly fixed to the pedestal The same goes for the pedestal feet.

[Christopher Mondt]

It was one of the LAMPFANS vibrating.

It was like that from the beginning of production of the projector...

Now we have a complely steady image.

Thanks for You help.


Christopher

[Ryan Gallagher]

It was one of the LAMPFANS vibrating.

It was like that from the beginning of production of the projector...

Now we have a complely steady image.

Thanks for You help.


Christopher

Awesome. That feels like the easiest fix out of the several suspected causes.