Film-Tech Forum ARCHIVE: vertical image shift

This is topic vertical image shift in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

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Posted by David Stone (Member # 4846) on 02-08-2012, 10:13 PM:

Hi Everyone,

I have a vertical image shift problem. Today the first session in 2D started with the image up 12 inches from the bottom masking. I adjusted using the lens settings.
The next 2D session played fine. The 3rd session was in 3D and the picture was again 12 inches above the bottom masking.I adjusted using lens settings. During the break I did some testing and the following are the results, If you start a 2D playlist it screens fine. The next playlist is 3D the image lifts. The next playlist is 2D or 3D the image lifts. However if you manually stop the playlist the next playlist if 2D is fine but if 3D the image lifts. I just had annual service last week and everything has been fine until today.

Cheers,

David

Posted by Dominic Espinosa (Member # 2122) on 02-08-2012, 10:22 PM:

what projector make/model is it?
You probably should call your tech back.

Posted by Manny Knowles (Member # 1171) on 02-08-2012, 10:27 PM:

I'm assuming that you are comparing the same aspect ratio, 2D versus 3D.

If you are comparing the same aspect ratio in both formats, you may have separate lens and/or screen files for your 2D versus 3D (even though they don't HAVE to be different). Any lens/screen difference between 2D and 3D would allow for the possibility that your 2D image could be correctly aligned to your screen, and your 3D out of alignment.

That 3rd playlist is troubling. What happens if you do the test again, with the playlists in a different sequence? Try running the first playlist last. Does it still line up with the screen?

If that playlist always lines up with your screen then I'd suspect there may be something odd with your files/macros. But, if it shifts inconsistently, then your lens motor may be on the fritz.

Posted by Justin Hamaker (Member # 2165) on 02-09-2012, 12:13 AM:

Sounds to me like your format selections lost the associated lens file. As Manny said, the 2D & 3D versions of each aspect ratio can use the same lens file, but you have to associate that lens file with the format.

For example, your format configuration would look something like this

2D Scope
Scope Lens file (zoom, shift, focus)
2D Lamp file (lamp power)
Scope screen file (position of image on chip and crop settings)
2D Color settings

2D Flat
Flat Lens file
2D Lamp file
Flat screen file
2D color settings

3D Scope 2048
Scope lens file
3D lamp file (usually higher power than 2D)
Scope screen file
3D color settings
3D settings

3D Flat 1998
Flat Lens file
3D lamp file
Flat screen file
3D color settings
3D settings

I know there are some other elements, but that's the basic idea. As you can see, various configuration files are common across multiple formats.

Posted by Manny Knowles (Member # 1171) on 02-09-2012, 12:19 AM:

Justin -- I'm curious why you include numbers in your 3D macro names, but for your 2D macros?

Posted by Justin Hamaker (Member # 2165) on 02-09-2012, 12:33 AM:

It's habit based on our first digital projector where we had Scope, Flat, 3D Scope 1920, 3D Flat 1920, 3D Scope 2048, and 3D Flat 1998.

Both of our 3D projectors are configured with the 3D 1920 formats just in case they are needed.

Posted by Manny Knowles (Member # 1171) on 02-09-2012, 12:44 AM:

Ah, got it. I use DCI as my 2K indicator. (e.g., DCI 1.85, DCI 2.39)

Posted by Jonathan Althaus (Member # 5042) on 02-09-2012, 09:53 AM:

Which type of projector was this?

Posted by Tony Bandiera Jr (Member # 2365) on 02-09-2012, 12:29 PM:

If David has a Christie, it is possible that the ILS (Intelligent Lens System) was not calibrated before making the lens files. I forgot to do this calibration on my machine at UC Irvine and will have to do it on my next service call. So far it has stayed in calibration, but they are not running DCP content yet so they haven't had to make a bunch of format changes yet.

If it is not calibrated, the ILS does not know the full range of motion on the lens motors and thus can drift easily.

Posted by Jonathan Althaus (Member # 5042) on 02-09-2012, 01:06 PM:

And if its a Barco, I'd suggest deleting the lens files, rehoming the lens, and recreating/resaving the files

Posted by Manny Knowles (Member # 1171) on 02-09-2012, 03:25 PM:

^ Yes. This is a good tip.

Although, I'm not convinced you have to actually DELETE the files. You can overwrite them (same filename).

If you do decide (or if your tech decides) to delete them and start over, please double-check your macros to verify that they refer to the new files. If the new filenames don't match the original ones, you'll get errors.

Posted by Pete Naples (Member # 761) on 02-09-2012, 04:39 PM:

Barco had some motorised lens issues on earlier firmware revisions, worth making sure it's all up to date.