Film-Tech Forum ARCHIVE: Digital IMAX 2D/3D Projection?

This is topic Digital IMAX 2D/3D Projection? in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=16;t=002840

Posted by Aron Toplitsky (Member # 6950) on 10-19-2016, 07:39 AM:

This past Sunday I went to the AMC Rolling Hills in Torrance CA, to see Interstellar for Space Week. I saw it twice in IMAX 15/70 when it was first released and I knew the digital IMAX version was not going to look nearly as good. A few trailers were shown and the last one prior to the feature, was a 3D trailer despite Interstellar not being a 3D movie. I could see the lens change over and an alert cued the audience to put on our 3D glasses. I feared the image for the presentation would be all screwed up, so I flew out of my seat and asked management to return the projector setting to 2D. I did notice the image was a little dark during the entire film, so my question..is it possible the projector switched to a 3D setting yet played the film in 2D? Does an IMAX projector work that way? I've read on this site how standard auditoriums suffer from a 3D setting for a 2D movie, which can cause a darker image. Does this apply for IMAX as well?

Side note: throughout the entire presentation there was a light reflecting onto the right side of the screen and was quite noticeable and distracting during dark scenes. I emailed IMAX and they immediately contacted me, saying they were going to correct it. I must say, I'm getting tired of there always being a technical issue when I attend movies these days. And I'm getting really fed up with inconsiderate movie goers. If I had the money to have my own kick ass set up at home, I'd NEVER go to the movies again!!

Posted by Dave Macaulay (Member # 813) on 10-19-2016, 09:27 AM:

There's no lens change over for IMAX digital 2D vs 3D. Motorized polarizer plates slide in front of the lenses. The dowsers shut while this happens, I think.
Showing a 3D trailer for a 2D movie MAKES NO SENSE! You are distributing, collecting, and washing 3D glasses for a trailer???
Playing a 2D movie through the polarizers... VERY BAD PRACTICE (I expect it from a multiplex, but IMAX is supposed to "do it right"). Light is reduced, focus is impaired, and the "special sauce" IMAX dual projector 2D magic resolution enhancer is turned off.
Probably the "booth usher" screwed up the playlist, making it 3D?

Posted by John Thomas (Member # 6509) on 10-20-2016, 08:28 PM:

The SMS detects what type of content is in a playlist and adds the appropriate cues to switch formats and set the filters/shutters, even between pieces of content. It will even automatically add appropriate snipes to notify the audience of format changes. Because of this I would be very surprised if the feature ran with the filters in. You can literally build a playlist with 3 different types of content and no cues, and it will automatically do all of the necessary format change cues by itself.

I would guess that somebody accidentally added the 3D version of a trailer instead of a 2D one by accident, but the system should automatically switch back to 2D if it is running 2D content.

Also keep in mind that the physical shutter goes Shutter->Filter->Open so when the shutter moves from closed to open you do see the filter for a moment during the transition.

Posted by Aron Toplitsky (Member # 6950) on 10-21-2016, 07:26 AM:

Interesting! Thanks for the response guys. Again the entire film was a bit on the dark side and the resolution was NO match for the 15/70 version, especially during the 15/70 shot scenes.

Posted by Bill Brandenstein (Member # 7758) on 10-21-2016, 10:23 AM:

Aron, there are other threads with lengthy discussions about Interstellar where we beat the resolution topic to death. I saw it in both versions and the 2K Liemax was wretched compared to the 15/70 version, which only proves how utterly stupid the moviegoing public is.

It shouldn't have been dark, however, which suggests something was wrong.

Kinda wished I'd known about this. That's one movie that just has to be seen on the big screen to work as intended.