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Author Topic: Periscopic projection David Kilderry Master Film Handler Posts: 355 From: Melbourne Australia Registered: Sep 1999 posted 06-01-2003 05:50 AM                        Hi Peter, At the former Hoyts Midcity here in Melbourne, they did almost exactly what you are contemplating back in 1976. It was a large twin with about 900 seats per house, they wanted to add a third screen, but lacked space. The solution was to take over part of the foyer for a 225 seater, yet there was no room for a projection room unless capacity was reduced considerably. The news stand in the arcade below was bought and it was transformed into the projection room using a periscope. The projection room had a Philips FP 20, platter and automation. The beam hit a mirror and went 30 feet up a shaft to the back of the theatre, it then hit a larger mirror and went to the screen. As the screen was small, light and focus were good. It was difficult to get into focus and I found I had to go up to the back of the theatre to check that it was OK. On hot days we would often have the door to the booth open, it sure got looks from passers by as they saw a projection room in the middle of an arcade. David Kilderry  |  IP: Logged Bernard Tonks Jedi Master Film Handler Posts: 619 From: Cranleigh, Surrey, England Registered: Apr 2001 posted 06-01-2003 07:01 AM                     Stephen wrote, quote: One of these, Waterloo I think, had the projection box built above the auditorium, with rear projection via mirrors, but it was later changed to a more conventional set-up, so I assume it didn't work too well. Bernard, if you read this, do you know any more about these places? Both have now been demolished, and I never went to the Waterloo one. Stephen, I know this will be hard to believe that the projection room at Waterloo was high above the auditorium shooting through a void directly onto a rear projection screen above the stage onto a vast mirror. You actually watched the 60 minute News programme on a mirror , this was in the early days of 4x3 academy ratio mind you, and designed to overcome the severe projection keystoning. Shortly afterwards this system was abandoned I assume due to problems with reflections on the mirror etc., and the projectors were steeply re-raked for direct projection. In later years Waterloo News Theatre / Waterloo Cartoon Cinema, became a Classic Cinema installing wide screen & cinemascope, with Cartoons during the day, changing to Double Feature programmes from 5pm, eventually full-time. I believe The BTH projectors were original from the opening day. I visited this place a couple of times during the Newsreels era, but never the Victoria Station one. One of the worst mirror projection system designs I saw although clever, was at the Compton Cinema Club in London’s Soho. Projection was from behind and beneath the screen through mirrors onto a main mirror in the like orchestra pit, which reflected the picture onto a wide screen. The projectors which faced each other about 15 feet apart, were Kalee 37s with xenon arcs on 2000’ changeovers which must have been automated as you could only see the picture in the auditorium.  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 06-01-2003 08:21 AM                     Cinepelx eaton centre had both periscopic front projection and rear screen booths There were several other periscopes in some of there other locations as well I was in one threatre once that had a downward periscope through the booth floor to a lower theatre  |  IP: Logged Fred Georges Master Film Handler Posts: 257 From: Lombard, IL, USA Registered: Jun 2000 posted 06-01-2003 06:24 PM                     Mirror projection is certainly a tricky business but, if done correctly is a viable approach. Astronomical grade front surface mirrors are a MUST for the primary. Mylars can be use to good effect for large secondarys but, if budget permits and the secondary is no larger then 30" by 30" I'll go with a front surface Mirror. I'm fortunate to have a custom manufacturer of Astro grade mirrors in my area and they have made Me some excellent ( though expensive) sets in the past. My main problem with large secondarys has been the distortion of straight lines. Even though the mirror backing support plate appears flat most times it isn't. Not the mirrors fault but the supports. In video installations it was easy to do a complementary distortion when converging the CRT projectors to get the correct, straight lined geometry on screen. With film & LCD/DLP projectors I found I had to pre "distort" large secondary mirrors with an adjustable torsional frame. I built one years go, and what a complicated beast it was with 24 adjustment points. It worked well for that installation but I'd hate to have do one again.  |  IP: Logged Bill Gabel Film God Posts: 3873 From: Technicolor / Postworks NY, USA Registered: Jan 2002 posted 06-02-2003 04:06 PM                     Cineplex's Beverly Center in Los Angeles had two perscopic theatres. But during the remodel to make the two large theatres up stairs they had to lost one of those houses.  |  IP: Logged Phil Hill I love my cootie bug Posts: 7595 From: Hollywood, CA USA Registered: Mar 2000 posted 06-02-2003 04:27 PM                  Periscopes and mirror configurations are commonly used in special venue and ride simulators to solve a myriad of projection throw limitations with both front and rear projection screens. Having designed and installed many of these, I agree with what George said in his above post. However, I would stay away from the Mylar mirrors if at all possible. In addition to the problems George mentions, I have found the large surface area of the thin membrane acts like a passive speaker/microphone diaphragm. The vibrations, especially from the subwoofers, cause the projected image to wiggle, go in-and-out of focus, and do other strange things on the screen and it is very annoying. ALWAYS use 1st surface mirrors if at all possible. >>> Phil  |  IP: Logged Timothy Eiler Expert Film Handler Posts: 126 From: Litchfield , Minnesota, USA Registered: Mar 2000 posted 06-02-2003 05:49 PM                        quote: Also in this town is a drive-in that has 5 screens, an 85, 50, and 3 30ft screens. The Screens are 100 ft,60 ft,2@ 32 Ft and the last is 36 ft Tim Starlite Drive-in [ 06-03-2003, 09:36 AM: Message edited by: Timothy Eiler ]  |  IP: Logged Daryl C. W. O'Shea Film God Posts: 3977 From: Midland Ontario Canada (where Panavision & IMAX lenses come from) Registered: Jun 2002 posted 06-02-2003 06:02 PM                        Whoa! This isn't the place for booking disputes. You guys (Tim & Peter) need to either pickup the phone or email each other. Don't discuss it here.  |  IP: Logged Timothy Eiler Expert Film Handler Posts: 126 From: Litchfield , Minnesota, USA Registered: Mar 2000 posted 06-02-2003 06:51 PM                        Had There Been no innacurate information posted about my Drive-In I would have had no need to respond and Would Not have. [ 06-03-2003, 09:37 AM: Message edited by: Timothy Eiler ]  |  IP: Logged Ken McFall Jedi Master Film Handler Posts: 615 From: Haringey, London. Registered: Apr 2001 posted 06-03-2003 12:32 PM                     Odeon Panton Street in London, formerly the Cinecenta, Cannon, MGM, ABC, is a four screen that uses periscope in all four screens. When it first opened it was all change-overs with eight FP20's with AEI/BTH 2k three electrode lamps. The rectifiers, westinghouse, were sunk into the floor or hidden under stairs. There were two booths with four projectors in each, it was like an oven in there. Eight set's of mirrors to clean and constantly adjust, the audience could reach in and move them. The operator looked out between their heads. Today they still have the same FP20's but they are down to four, now running with two Kinoton platters upstairs and two Cinemeccanica towers downstairs. The lamphouses are converted Orcons that run off Irem rectifiers...and all connected to an installation that has to be seen to be belived! Odeon are 'Fanatical about film' by all accounts in this West End show. But the mirrors remain!  |  IP: Logged Tim Reed Better Projection Pays Posts: 5246 From: Northampton, PA Registered: Sep 1999 posted 06-03-2003 07:53 PM                       Speaking of mirrors, you should have seen one of the mini drive-ins; those were the ones that had 160-some-odd little screens, built in a circle around the booth. Each car parked in front of its own little 3 x 5 screen. I remember there were a ton of mirrors to pull this arrangement off, and by the time the image(s) hit the rear-projected screens, there wasn't much light left to view.  |  IP: Logged System Notices Forum Watchdog / Soup Nazi Posts: 215 Registered: Apr 2004 posted 04-02-2005 03:20 PM                 It has been 668 days since the last post.  |  IP: Logged Ferdinando Innocenti Film Handler Posts: 79 From: Genova / Italy Registered: Jun 2004 posted 04-02-2005 03:20 PM                     Well, I was wondering if it is possible, and if the equipment needed exists, to build a booth in which the turret is not installed on the projector. My thought: where the lens should be, you can mount a mirror (45°), then another mirror (periscopic projection), then the turret on a bracket. I think it could be better if the light should pass in a rod, such as the integrated rod in Barco DP100. Do anyone of you know if a system like this exists? Do you think the light loss is much more than in a normal periscopic projection?  |  IP: Logged Adam Martin I'm not even gonna point out the irony. Posts: 3686 From: Dallas, TX Registered: Nov 2000 posted 04-02-2005 04:18 PM                     You would never achieve focus with the lens being so far from the film plane.  |  IP: Logged Tim Reed Better Projection Pays Posts: 5246 From: Northampton, PA Registered: Sep 1999 posted 04-02-2005 09:50 PM                       What would be the benefit of relocating the turret?  |  IP: Logged

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