Film-Tech Forum ARCHIVE: What's Giantscreen ?

This is topic What's Giantscreen ? in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

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Posted by Nguyen Jack (Member # 7530) on 03-05-2015, 09:36 PM:

Hi everyone,

I'm very interested in Giantscreen technology
Can you recommend me how big screen technology (Giantscreen) ?
How to calculate the size of the screen ?

And can you get for me some document of technology.

Thanks.

Posted by Dave Macaulay (Member # 813) on 03-07-2015, 08:20 AM:

The industry group (GSTA = Giant Screen Theatre Association) defines what qualifies a theatre to join their organization:

quote:
What is a giant screen?
Participating giant screen theaters must meet the following requirements.
Giant screens are at least:
70 feet (21.3 meters) wide, or
3,100 square feet (288 square meters) in total area for flat screens, or
60 feet (18.3 meters) in diameter for domes, and
Place all seating within one screen width of the screen plane

Most of these are institutional - museums or such - and have screens with an aspect ratio close to the 1.43:1 that IMAX used with their original 15/70 film projectors.
Digital projection filling giant screens has not been practical: you need a LOT of light to get a reasonable image. 4K looks pretty good on a very large screen though. Laser light source projectors may overcome this problem, multiple xenon projectors is another possibility. The worlds truly giant screens use 15/70 film projectors with 15kW+ xenon lamps for now.

Note the above definition is only for joining the GSTA. You can call your basement home theatre "Giant" if you want. You could call an ipad a giant screen theatre for that matter - there is no trademark or such on the term "Giant Screen" that I can find. However: the GSTA owns "Certified Giant Screen®"... so don't use that (unless it is).

Posted by Danial Simmonds (Member # 4638) on 03-08-2015, 06:46 AM:

Interesting indeed, but wouldnt laser projection settle the issue with the amount of light needed?

The viewing angle an depth of the auditorium would be important in a large screen design.

Posted by Dave Macaulay (Member # 813) on 03-08-2015, 08:14 AM:

Definitely the viewing angle is important to the GSTA. I wouldn't have a problem calling a huge stadium Jumbotron® a "Giant Screen". Architectural video projections turn stately homes, castles, office buildings, etc into "giant screens".
A giant screen cinema should, in my opinion, have an immediate impact when you first enter the auditorium and see the screen dominating the room.
I did not see the pavilion where 15/70 debuted at Expo 70 in Osaka. According to first hand reports the building did not exploit the image well, but did hint at what it could be - as I understand it the projector (from the company that would become IMAX®) had until then only run in a small room and the pavilion was the first place 15/70 was seen on any "large" screen.
I was in Cinesphere the year it opened and found it overwhelming - unimaginable to someone expecting an experience like the movie houses of the time. In the flying scenes much of the audience (me too!) believed the whole theatre was pitching and yawing.
I believe a "Giant Screen Cinema" should maintain that "wow" effect. The screen should be very large and the audience should be close. Installing a 50M screen facing out of a stadium end zone would be impressive, definitely a "giant screen", but would not have the impact of a true "giant screen theatre".
Looking at historic images of the original 1000+ seat Movie Palace rooms it's easy to idealize their complex architecture and decoration; if you look at the screen though, it's a tiny postage-stamp square in the massive ornate proscenium. Probably patrons in the rear rows needed opera glasses to see the image. A typical modern stadium seating cinema would astonish those folks the same as I was astonished at Cinesphere in 1971.
A giant screen theatre should have the same effect on people used to the modern cinema experience!

Posted by Terry Lynn-Stevens (Member # 7349) on 03-08-2015, 01:58 PM:

quote: Danial Simmonds
The viewing angle an depth of the auditorium would be important in a large screen design.

If you read some of the original design documents from IMAX back in the early 70s, viewing angles and grain reduction were first and foremost the most important element of the IMAX design. That along with 15/70 film and their soundtrack and speaker design. The IMAX GT Theater and the smaller theater design that were introduced in the late 90s is patented so someone just can't come along and copy the design. The IMAX Scotiabank in Toronto and the Colisuem/Colossus IMAX are such examples of the larger GT Theater and the smaller (I think its called SR Theater) designs that are currently out there.

Posted by Jarod Reddig (Member # 6363) on 03-08-2015, 03:24 PM:

Very interesting thread. I havnt yet heard of the GSTA until now. Much agreed Dave about what a "GiantScreen" should posess and the impact it should have on the audience.

Posted by Nguyen Jack (Member # 7530) on 03-08-2015, 10:42 PM:

Thanks Dave,

So Frist,
how can I do that, I need to how to build it?
second:
Mandatory 70 feet (21.3 meters) wide, or
3,100 square feet (288 square meters) in total area for flat screens, or
60 feet (18.3 meters) in diameter for domes
Can I design smaller ?