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What I REALLY want to see is a picture of the IMAX projector. Nothing too fancy... just something like, "The film goes in here, through this doohicky, around this thingamabob then comes out here. (Or whatever.)

Click Here

(remember to click on the red oval SDDS icon)

with the left and right channels on the walls. interesting

In this case, it seems like there was absolutely no communication whatsoever -- don't just look at the SDDS -- that diagram was used throughout the movie sound article. Not only doesn't it show the additional screen channels for SDDS; it also seems to believe that Dolby Stereo has only two channels and has completely left out the left and right surrounds. But I suppose we can't expect all illustrators to be experts on motion picture sound.

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"The Rolling Loop -- A New Concept of Film Transport", by P. R.(Ron) W. Jones, SMPTE Journal, January 1968, pages 21-23

"Film Dynamics of a Rolling-Loop Film-Transport System", by William C. Shaw, SMPTE Journal, September 1970, pages 778-782

"New Large-Screen and Multi-Image Motion-Picture System", by William C. Shaw, SMPTE Journal, September 1970, pages 782-787

Technical achievements like this make you proud to be a member of the SMPTE.

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John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Eastman Kodak Company
Research Labs, Building 69, Room 7419
Rochester, New York, 14650-1922 USA
Tel: 716-477-5325 Cell: 716-781-4036 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion

other things he explains on the site can be somewhat more complex. a question was submitted concerning what makes super glue so super ( http://www.howstuffworks.com/question695.htm ). he went into the main chemical makeup and how it reacts to make polymer bonds and what not. i mean, its basic chemisty but if you know nothing about chemistry in the first place, then its a good thing to get a brief explanation.

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John Walsh is correct that the SMPTE is in the process of putting articles on their website. For now, they have put indices and more recent articles and presentations "on-line". You can join the SMPTE and subscribe to their library service at:
http://www.smpte.org/membership/

The SMPTE "members only" library is at:
http://www.smpte.org/members_only/

You can work with your local library to get copies of articles published in the SMPTE Journal. Libraries that subscribe to the SMPTE Journal would include film schools (e.g., UCLA, USC) and science/engineering schools that teach film or television technology (e.g., Rochester Institute of Technology).

- Only a few very old water cooled Imax/Omnimax systems use 12kW lamps. Since around 1985 or so all have been 15kW. There are a fair number of 4 and 4.5 kW air cooled ones as well, and one or two 7kw (maybe, if they are still running and have never upped to 15kW) aircooled "classic" machines.
There are 2 Imax "Solido" 3-D single case 2-strip cameras with a fixed interocular, dictated by the lens diameters when it was designed. With 1000ft magazines it's probably in the 240 pound range. There can also be a 3D rig with 2 "standard" MK1 Imax cameras at 90 degrees with a 45 degree mirror. This thing weighs a bit more, and has a gyro stabilized mount available that probably weighs as much again. The first 3D Imax film, made for Expo86 in Vancouver, used this one. Imax doesn't seem to want to admit to this movie, it isn't on their film list and I can't even remember the name. Transitions? It had the teddy bear scene, and the robot arm breaking an egg in your lap. The twin rig was used on The Last Buffalo and also Imagine - if that's the one with the little people - as the freedom to mess with interocular was needed for that effect. There was also a 3D rig with the cameras about 6 feet apart for some weird forced shots.
There are many problems with the mirror rig - it takes a LONG time to set up using reticles projected from the cameras onto a screen for alignment. This needs a large dark area, obviously... Plus, the amount of cabling and electronics is a nightmare.

- The author talks about 48fps as if it's a standard feature. Not. There are almost zero 48fps films and only a few more projectors that can show 48. Ontario Place and Hull are the only ones I'm sure of. The cameras get very snarky if expected to run at 48 for long (it's about the limit for the standard camera) and the projectors like it even less. The film is moving twice as fast, and has to be stopped and accelerated again every frame. The inertial energy is proportional to the square of the velocity...

- 20 minutes to reload? Nonsense. The 3D one maybe, but a decent camera operator can do a 2D mag change in about 5 minutes maximum - with a good cleaning thrown in. We can't count the time to reload the mag, an assistant does that in a dark bag during shooting.

- 3 minute rolls? OK, but there are also 2000' (6 minutes...) magazines and Kodak did supply 2000 foot 65mm neg rolls. These were made for the Stones movie, to cut by half the mag changes. Filming theirive show apparently made the effort worthwhile. There are also 300' mags for shots where weight or size is a problem, they were used in the infamous Catch the Sun skydiving shoot that may have financially saved Imax in the early days.

- There are lots more than 2 cameras of course. Camera #2 was the one used trying to parachute but there were about 8 working ones the last time I looked. 2 of these were reserved for only spaceflight though.

- There are at least 2 very different generations of 2D Imax camera, the solido Imax3D ones, plus as the competition's 15/70 models) which we shouldn't call Imax of course).

Plus, it didn't even really tell us how it works!

I have a bunch of photos somewhere, if I get ambitious I will try to find one that shows the front end of a projector. If anyone (Gord?) can scan a threading diagram from a manual that would be excellent!