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This topic comprises 3 pages: 1 2 3
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Author
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Topic: More light? Is it possible?
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John Pytlak
Film God
Posts: 9987
From: Rochester, NY 14650-1922
Registered: Jan 2000
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posted 12-13-2000 11:02 AM
Jerry Chase asked: "does anyone know if the ultimate drive-in was ever tried? By that, I mean finding a place in the
middle of nowhere with no light contamination and projecting a full feature film onto the base of a cloud cover."When I worked at the Grandview Drive-In, I tried that several times, reflecting the projector beam up with a mirror. But the clouds were always too high and I did not have a lens with the correct (very long) focal length. When the cloud cover was lower, it usually was foggy as well. It would be kind of neat to develop a projector that could put a movie (or even still) image on low clouds, to use for advertising. I wonder what kind of projector they use to project the bat symbol on the clouds to signal Batman? ------------------
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 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com
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Dave Bird
Jedi Master Film Handler
Posts: 777
From: Perth, Ontario, Canada
Registered: Jun 2000
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posted 12-13-2000 04:23 PM
Hey, cool, you could lie on your blanket and watch the show! Speaking of "alternative" DI's, anyone ever hear of a ski resort that, once the snowbanks piled high enough in the parking lots, would "cut" a flat white screen with the groomers and have a winter-time drive-in? I've never heard if this was (or is) a continuing thing, or just once or even WHERE they did it. I've talked to some skiers who'd heard of it, but no-one knows where. Anyone know?John- no light here, I've got projectors, film, damn, no lamps  ! Jerry- I found my samples of that 3M Scotchlite reflective stuff. Very directional as well. Wonder if they could make it suitable for film? Certainly the drive-in market wouldn't be enough motivation for a company like 3M, but could such a material allow for better light output at any theatre with smaller lamps???
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Pat Moore
Master Film Handler
Posts: 363
Registered: Mar 2000
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posted 12-14-2000 08:21 AM
Nice to be out of airplanes again...for a while, that is.In our company, Simplex used the only high speed intermittent that I'm aware of. I don't think Century did one, but used the double-shutters to improve light efficiency. We have fooled around with them in Ballantyne but for different purposes and not necessarily light efficiency improvement. For your big beam projector, Strong makes a "P3 Pattern Profile Projector". This thing can project an image on a mountainside or a building a mile or more away. Take a look at: http://www.xenotechusa.com/html/body_p3.html Pat
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Jerry Chase
Phenomenal Film Handler
Posts: 1068
From: Margate, FL, USA
Registered: Nov 2000
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posted 12-14-2000 09:03 AM
Dave, IIRC, they make the reflective beading for this stuff by spritzing hot glass into the air, where it solidifies in the form of tiny spheres. That makes the spheres inexpensive, and it is only a matter of sizing and binding them to complete the product. Getting a wider angle of reflectance isn't possible with this technique, which is why some "lenticular" screens have used "silver" paint molded into various bumps and valleys.If you want to play around, you can get bottles of the larger glass spheres. They are sold as an additive for reflective parking lot paint. Long before the nice reflective car finishes commonly available today, I added some of these to an overcoat paint job on a hot car I had. The surface was bumpy as hell, (almost like sandpaper)but it did reflect, kinda like today's license plates. I guess micro-etching techniques could create a roller/mold for a super high gain directional screen, which could then be surfaced with a thin layer of chrome, but I think the costs would be outa sight, and the angles would have to be tailored to whether the surface was going to be screen right, screen left, or center. Otherwise light fall off at the edges and hot spots could be a problem, depending on your viewing position.
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Paul G. Thompson
The Weenie Man
Posts: 4718
From: Mount Vernon WA USA
Registered: Nov 2000
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posted 12-14-2000 05:49 PM
I think most of your problems might be in the lamphouse itself. You might want to consider an upgrade. Also, the screen might need to be repainted, and check the shutter in the Simplex. It is (at least on the older machines) adjustable. I am not certain if there is a "drive-in" shutter made for the XL or not. If you open the shutter to allow more light through, check for travel ghost on the screen. If it is ghosting, you'll have to adjust the shutter so it does not ghost. Be careful, though. If your shutter is out of time, you will have a ghost in one direction or the other, depending if the timing is early or late. (what I mean by opening the shutter is to loosen the screws on the blade and "collapse" it, then re-tighten the screws). you may want to check your shutter timing after you do that. If you look at the screen while credits are rolling, and your shutter is timed properly, if your shutter is open too much, you might have equal ghosting on the top and bottom of the credits. You might consider trying these things first before you spend a ton of money and find out that you didn't have to. ------------------
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Steve Guttag
We forgot the crackers Gromit!!!
Posts: 12814
From: Annapolis, MD
Registered: Dec 1999
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posted 12-14-2000 06:48 PM
Mark, I gotta disagree with you on the scrapping of the Simplex projector. The Century has a massive block to collect the heat, Simplex tries to reflect the heat away or project it through. There is nothing wrong with using a Simplex with larger lamps, with water cooling with or without the "dirt pump!"The big improvement will be the replacing of the lamphouse with one that gets more light out (as just about everyone has already stated). I agree that the Kinoton lamphouse is the only one I have seen/used that I would put a 7000 lamp in and run 35mm film. I see a big improvement from going from a 4000 to a 5000 watt lamp without the big heat increase (OSRAM lamps). Christie now has a 6000 watt lamp they claim is as good as gold on the light vs heat. That is, they claim their 6000 watt lamp (CXL-60) has more light output that the 7000 and less heat. Again, I would start the improvement in light by changing the lamphouse over to an Ultra-80 or a Kinoton Universal (easier to adapt the Ultra-80 to American pedestal). Also, consider finding some 4" diameter lenses if your focal length is in the 7" range. The old B&L Super Cinephores are actually quite good. With really long focal lengths (greater than 140mm), the lens is a limiting factor of how much light can get out. Steve
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