Film-Tech Forum ARCHIVE: Christie 2230 Convergence Calibration

This is topic Christie 2230 Convergence Calibration in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

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Posted by Lucas Iaccarino (Member # 8762) on 03-10-2017, 06:32 PM:

Hello.

I´m having some convergence troubles with some Christie 2230 in a couple of Screens. The Technical manager says he doesn´t know how to calibrate them, so we are waiting for Christie Service. Could you tell me if it´s that difficult? For Barco Projectors is so easy to access there.
Thank you very much

Posted by Dave Macaulay (Member # 813) on 03-10-2017, 10:59 PM:

Convergence of a Christie 2220/2230 is nowhere near as easy as with a S2 Barco. To be fair though, Barcos slip out of convergence a lot more often than Christies (but take 5 minutes to fix).
It requires fairly standard tools although Christie sells a convergence tool kit. I think there's also a convergence manual separate from the normal service manual.
It is not fun. Don't try it with a deadline looming.

Posted by Carsten Kurz (Member # 5396) on 03-11-2017, 04:30 AM:

For a quck fix, if there are larger overall convergence errors, there is an electronic convergence option accessible on the touch screen. Everything done there should be reset when doing mechanical convergence.

- Carsten

Posted by Lucas Iaccarino (Member # 8762) on 03-11-2017, 07:05 AM:

I Understand. So my best choice is to try the electronic convergence and then wait for Christie to repair it. Anyway I will look for the convergence manual you said.

Thank you very much

Posted by Stephan Shelley (Member # 8587) on 03-11-2017, 11:58 AM:

I think there is a tech note about problems with the electronic convergence and to use the mechanical.

And I second about it not being easy. Adjustments are down deep behind the formatter boards where they mount to the prism frame and locking screws accessed through holes in the formater boards.

Posted by Steve Guttag (Member # 268) on 03-11-2017, 02:25 PM:

Christie is pretty good about having the tools tucked under the covers. Adjusting the convergence is NOT for the faint of heart or for the experimenter. Small adjustments have great changes and you could very well make things worse. On the Christie CPxx30 series, there is also an air duct that has to be moved to gain access to some controls and while it is out of position, you are now running the risk of overheating the DMDs (you get precious little time).

I HIGHLY recommend the USL CCT camera for convergence. It can cut your time in quarters, if not tenths. Typically, with covers removed and a lot of light splashing around, using binoculars or a spotting scope can be tricky. You should have UV protection on so using those devices can be even more tricky. Plus, when looking at primary colors, the index of refraction becomes more apparent so blue will look like it is "behind" the other colors.

The electronic convergence is only supposed to be problematic on the 4K DMDs (and the S2K, I believe too). That said, it isn't convergence in the true sense, it merely is pixel shift so you can move the convergence in whole pixels. So if your convergence is off by a pixel or more, then yes that is the quick and dirty way.

I tend to agree with others, if you have a bad convergence problem, use the electronic convergence until they can be mechanically set right by someone with the proper equipment and training.

Posted by Marco Giustini (Member # 4544) on 03-11-2017, 04:17 PM:

I would assume that UV has already been removed by the UV filter just before the engine vane?
Recent Christie engines don't need the DMD's to be loosened, they're spring-mounted like Barco's but they don't have the extenders. This make the adjustments much easier.
However, if you touch ANYTHING with a metal tool you'll then need a new engine which is going to be very expensive so I second everybody else's advice of NOT to attempt convergence if you have not been trained.

Posted by Stephan Shelley (Member # 8587) on 03-11-2017, 04:24 PM:

The spring loading I think started with the 4K prism. Not sure they ever did the 1.2 or .98 chip 2Ks,

Posted by Marco Giustini (Member # 4544) on 03-11-2017, 04:37 PM:

they said they were hoping to apply the same design on other engines. Not sure what happened then.

Posted by Lucas Iaccarino (Member # 8762) on 04-17-2017, 12:41 PM:

Already resolved. The Technical Manager fix it.
Thanks