mo@seismo.UUCP (Mike O'Dell) (03/10/84)
At the Toronto IMAXathon, a person from IMAX, Inc. talked about the project. He indicated they were building a special camera with a lense turret to switch between IMAX and OMNIMAX optics. The intent would be prints of the movie for BOTH formats. The story at that time would be that the camera would be mounted on a payload pallet so it would not only look out of the cargo bay, but could be set out in free space so it can photograph the orbitter against the Earth, deep space, etc. Most *MAX films are about 20 minutes long, but the rumor is that this one may be over an hour in length. One other thing to contemplate: this mission is also the one where they will fix the Solar Observatory. We might get footage of Man working in free space, and we might well have the first free maneuvering photographer!! I dunno when the film will be released, but if it fulfills half of its potential, it may well be a Religious Experience. -Mike O'Dell
dmmartindale@watcgl.UUCP (Dave Martindale) (03/17/84)
I'll believe that the film will be an hour long when I see it! Current IMAX films are limited to 35 min or so because that much film fills the film supply reels, which are about 4 feet in diameter and weigh hundreds of pounds when filled. To show a 1-hour film they would either have to modify the supply and takeup reel transport, or have an intermission while reels were changed.
geoff@callan.UUCP (Geoff Kuenning) (03/25/84)
Dave Martindale says: > To show a 1-hour film they would either have > to modify the supply and takeup reel transport, or have an intermission > while reels were changed. Why can't they do it the way a regular movie theater does it? A standard reel of 35-mm film lasts about 20 minutes. Each reel begins with a short section that duplicates the end of the previous reel. A simple method allows the projectionist to start the second projector in sync with the end of the first reel; she then simply presses a button and voila! a shutter falls in front of projector 1 and is raised from in front of projector 2. At the same time, sound tracks are also switched. Is it the extremely high cost of the IMAX projectors that prevents this method from being used? Or must they be perfectly aligned with the screen, so that it is impossible to have two side-by-side?
ron@brl-vgr.ARPA (Ron Natalie <ron>) (03/26/84)
It is both the high cost (all though this is probably just an excuse) and the fact that an IMAX projector, with it's reels is a big sucker. You just couldn't fit two of them anywhere near close to being on axis. The OMNIMAX at the Fleet Planetarium in San Diego barely fits as it is. The projector is threaded below the floor and hauled up into position by chains. The reels stay put, making a rather long run. The IMAX in the Air and Space Museum in D.C. has two 35/70mm projectors, one to each side of the IMAX projector. They're not really good because they have to be so far to the sides of the projection room because the IMAX projector takes up so much room. -Ron
dmmartindale@watcgl.UUCP (Dave Martindale) (03/26/84)
The projectors are indeed enormous compared to normal film projectors. The mechanism which transports the film past the gate is a machined drum several feet in diameter. The supply and takeup reels are each about 3 feet in diameter, although they don't need to be located directly with the projector. And the magnetic sound film handling equipment, air compressor, water supply, and arc power supply all need to be located somewhere nearby. But I suspect the main reason that there aren't many (if any) two-projector setups is that the projectors cost about half a million dollars each. I did once see a demonstration that used two IMAX projectors, polarizing filters, and a half-silvered mirror to show a 3-D test film made by the National Film Board. The illusion of depth was amazing. I felt like I could reach out and touch the objects that were sitting there right in front of me. This demo was at the IMAX factory (near Toronto) and someone commented that it was even unusual for them to have two fully-assembled projectors sitting around not in the process of being shipped to someone. of the hemispheric screen to produce a proper image, so there simply