Film-Tech Forum ARCHIVE: digital projection on a giant curved screen

This is topic digital projection on a giant curved screen in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

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Posted by Jonathan Goeldner (Member # 4854) on 06-16-2011, 04:30 PM:

I've noticed on the Uptown screen here in DC that the image slightly bows at the corners of the curved screen with the new Christie dual projector 3D projector (this wasn't a problem with the 35mm/70mm projector) - apparently this is also an issue on the Arclight Cinerama dome screen. Granted there are not alot of screens that have such a degree of curvature - I gather from talking with the manager, and a couple of online sources the DCI specs don't have solutions to this problem - is this correct?

Posted by Carsten Kurz (Member # 5396) on 06-16-2011, 07:33 PM:

For 35mm, there have been special lenses for curved screens. Digital projectors feature universal zoom lenses for flat field. I think there is nothing in the DCI spec that disallows special lenses, if the image quality is not degraded. I doubt, however, that someone will make such lenses for a digital projector. All current DCI projectors only allow non-linear masking, but not non-linear image correction like curved distorsion.

- Carsten

Posted by Paul Linfesty (Member # 214) on 06-16-2011, 07:39 PM:

quote: Jonathan Goeldner
apparently this is also an issue on the Arclight Cinerama dome screen.

As it is with 35mm/70mm projection in the Dome.

Posted by System Notices (Member # 2357) on 07-17-2012, 04:55 PM:

It has been 396 days since the last post.

Posted by Jonathan Goeldner (Member # 4854) on 07-17-2012, 04:55 PM:

according to "danstheday" over at Cinema Treasures, he's stated that there's talk about the curved screen at the Uptown Theater might being replaced by a flat screen - can't say that news is a good thing but it is a solution.

Posted by Monte L Fullmer (Member # 2797) on 07-18-2012, 12:22 AM:

It's really a simple fix to rid of the 'frown' in the corners:

All the operator/tech have to to is go into the program on the projector to adjust the default image settings to where the corners are lifted to compensate for the curved screen.

Takes a minute to do this adjustment with a grid test pattern on the screen.