quote: Andrew McCrea

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How is an 80' screen possible?

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quote: Andrew McCrea

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What kind of throw would you be looking at, and would 600 seats sound reasonable?

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quote: Andrew McCrea

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What xenon wattage would be acceptable and what equipment would be best for the most heat reduction/brightest image, etc.

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This is the real "nut cutting" point.

Opinions vary on how much real light ouput is capable from a 35mm lamphouse. Some say as little as 4000 watts. Others may push the total up to 6K or 7K. At either level, you're under budget for a 80' wide screen. You need something on the order of a 10,000 watt lamp to hit 16 foot lamberts at center and 12 foot lamberts at the edge on a 80' wide screen. 70mm projection is the only commercial projection format which can manage that.
 

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Posted by Thomas Hauerslev (Member # 566) on 04-20-2006, 01:03 AM:
 
The worlds largest screen in 1996 - 40 meters (131 feet)
 

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Posted by Louis Bornwasser (Member # 3063) on 04-20-2006, 06:00 AM:
 
80 ft screens do not tolerate fools easily. There is an old letter from Strong showing that lumens above 4000 watts does not increase (with that reflector) unless you go to 70mm.

A curved, gain screen is mandatory. Super 80 lamp/JJ projector/Schneider lens, new Hurley Superglo and a "3/4" radius curve on the screen. 16 fl/flat 22 fl/scope 28 fl/70mm Theatre was 950 rocking (big) seats, Cinerama design; angles were PERFECT. Louis
 

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Posted by Steve Scott (Member # 630) on 04-20-2006, 10:40 AM:
 
In Minneapolis there are four 80 ft. (give or take) monsters. Carmike has two of them in their 15-plexes on the north & south sides of the metro, Marcus has their Ultrascreen on the northeast side of St. Paul, and Mullers just finished their "monster screen" at my old home Lakeville.

The Carmike machines run 4.5 or 5K bulbs (I think) with basic Christie machines. The results are shaky, scratched & for years the digital sound wouldn't kick over. Sadly, these were the only THX houses too.

I haven't seen Lakeville's new monster yet. I'd heard installers were trying to talk up a JJ/cinefocus setup on a 4.5K bulb, but Muller ended up going with an SA brought down from the White Bear Township theatre & some German 6K bulb. A QSC tri-amp crossover was also supposed to be installed behind the screen. The cinefocus setup also went by the wayside. I've heard good things, but I thought they'd drop the 'monster screen' billing from their ads. It's a circus in the suburbs.

Marcus has a good setup with a Kinoton machine, not sure of the bulb. Some coworkers of mine saw Serenity there & only complained about the fader being set too low for such a setup. They are THX triamped.

Most of these auditoria have a square design, rather than being long & narrow. I don't like these. It gives an IMAX, right up there effect, unless you're toward the back of the house, which just doesn't sit right with me for 35mm.
 

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Posted by John Pytlak (Member # 331) on 04-20-2006, 12:52 PM:
 
To give some idea of the challenge of lighting an 80-foot wide screen properly, with typical 35mm projection efficiencies, a matte white (gain=1) screen would need close to a 15,000 watt lamp to light a 80 X 33.5 foot screen --- of course, if there were such a lamphouse, the 0.825 X 0.690 inch frame of 35mm film would suffer severe heat damage.

In practice, a 6K or 7K lamp with an efficient optical system and very efficient heat filter, a water cooled gate, high efficiency lens, and properly curved/tilted high gain screen may barely get you to the low end of the tolerance allowed by standard SMPTE 196M.

This is really a job for 70mm film!!!
 

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Posted by Scott Jentsch (Member # 1681) on 04-20-2006, 04:57 PM:
 
Instead of trying for a single 80' screen, I wish theaters would install more screens that were in the 50'-55' range.

There are far too many 26-footers, which are just too small to make the kind of impact going to the movies should provide. Unless that 26-footer is going to be in a nicely-appointed screening room type of environment, it's too small!

If your theater is considering installing a monster screen, talk them out of it and tell them to take the money they would spend and upgrade all of their auditoriums.

Having one huge one also makes the 26-footers in the other rooms look really tiny...
 

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Posted by Richard Fowler (Member # 893) on 04-20-2006, 07:22 PM:
 
Typical "warehouse" and shopping center building typically have 30 - 31 foot spans between roof support pads = 26 foot screen with an exit door
 

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Posted by Andrew McCrea (Member # 674) on 04-20-2006, 09:37 PM:
 

quote: Scott Jentsch

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If your theater is considering installing a monster screen, talk them out of it and tell them to take the money they would spend and upgrade all of their auditoriums.

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This is just personal interest, and what I asked people not to say.

I want to know how any theatre could do a 35mm screen in a width of 80'. Kind of with the short throw, etc. that's common in a multiplex.

So, what I've gathered:
-around 6 or 7kw.
-very efficient optical system (what's this?).
-very efficient heat filter.
-water and air cooled gate.
-high efficiency lens (Isco RED Ultra-Star HD PLUS?).
-high gain screen (what kind of gain?).
-screen properly curved and tilted.

Is this a job for Kinoton? I've heard really good things about the steadiness of their projectors and the efficiency/output of their lamphouses.

Then, I've also heard Christie mentioned as well, and someone even said something about it in this post.
 

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Posted by Matthew Bailey (Member # 601) on 04-20-2006, 10:19 PM:
 
A white laser type lamphouse would be ideal for an 80 foot scrren for 35mm but one of the limitations would be image grain. Lasers would produce little or no heat unlike xenon or carbon arcs.
 

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Posted by Andrew McCrea (Member # 674) on 04-20-2006, 10:34 PM:
 
What's a laser type lamphouse?
 

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Posted by Bobby Henderson (Member # 840) on 04-20-2006, 11:10 PM:
 
Laser Lamphouse???


Is that like a new version of that mirror covered ball they used to put in discos?

The big Cine Capris auditorium at Harkins Bricktown 16 in Oklahoma City puts out about as bright an image I've seen 35mm throw onto a giant sized screen. That screen measures 70' across and about 30' in height. A Kinoton projector is used in that booth (probably with a 7000 watt lamp, liquid cooled gate, custom reflector, etc.). I'm sure Harkins has tried hard to get as bright an image onto that screen as possible with 35mm gear. Yet it is just a tad dim for my liking. 5 perf 70mm would do a much better job.
 

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Posted by Andrew McCrea (Member # 674) on 04-20-2006, 11:50 PM:
 
Do they actually make prints that are printed a tad lighter for very large screens, or is this just an industry myth?

I'm glad I'm not the only one who doesn't know what that is.
 

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Posted by Frank Angel (Member # 248) on 04-21-2006, 12:50 AM:
 
There's a company called Technilite or something similar who claim to have developed a proprietary bulb/reflector system that increases light output by 1/3 more. It is being installed primarily in light-starved Drive-ins where an 80 foot screen is nothing out of the ordinary. Of course they don't get near the 16fl goal either; in fact, the SMPTE gave up that goal and only aims for 12ftl. Nor do DIs have the advantage of high gain screens (they paint corrigated steel or plywood with white paint -- gain of 1.0 at best).

So seeminly if DIs can get viewable pictures on those mamouth screens with whatever new technology this Technilite uses, it is conceivable that an indoor with the advantages it has of controllable ambient light, high gain screen properly curved and tilted, an 80 footer should be do-able. But then again, at what cost in image degradation due to such extreme magnification, especially if you a pushing seats up right up to the screen at the same distances that those shoebox theatres do, in other words, way WAY to close. Theatre designers seem to put those first rows at the same insanely close distance with total disregard to the screen size, matter if it is a 25ft screen or a 60ft screen -- the first rows are almost never at the SMPTE recommended distance, which is supposed to be determined by the screen size, not how close they can get the first row and still let people pass across it.

Knocking down the screen size in this hypothetical new build to 65 or 70 feet might move it enough away from the everything-is-super-critical-and-right-on-the-edge-of-scorching-the-film, and into the realm of reasonable. Wouldn't it be better to have a slightly smaller screen with a noticably superior image than a monster screen with a mediocre image?
 

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Posted by John Pytlak (Member # 331) on 04-21-2006, 08:56 AM:
 
For screening rooms, standard SMPTE 196M specifies the preferred viewing distance is between 2 and 4 times the height of the image. So for a 20 X 48 foot screen, the preferred viewing distance is between 40 and 80 feet from the screen, along the centerline of the theatre. Of course, most theatres have additional seats closer than this distance, and farther than this distance.

quote: Andrew McCrea

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Do they actually make prints that are printed a tad lighter for very large screens, or is this just an industry myth?

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quote: Richard Fowler

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Typical "warehouse" and shopping center building typically have 30 - 31 foot spans between roof support pads = 26 foot screen with an exit door

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quote: Louis Bornwasser

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Maybe we need "a light amplifying crystal." Louis

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I think those were made bu the Krell People... but alas they now only make fine audio gear .

Mark
 

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Posted by Gordon McLeod (Member # 33) on 04-23-2006, 02:49 PM:
 
which is no big deal as the kinoton or the ernamann lamphouses all do that right out of the box
 

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Posted by Mark Gulbrandsen (Member # 72) on 04-23-2006, 02:53 PM:
 

quote: Gordon McLeod

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which is no big deal as the kinoton or the Ernamann lamphouses all do that right out of the box

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