This is topic What is reason for HUGE projection ports in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.


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Posted by Brad Allen (Member # 470) on 12-16-2005, 01:46 PM:
 
Ok, I'm from the days of normal size projection ports that were rigged to enclose the booth in such a way the projectionist would be sacrificed in case of a projector fire.

So why did the trend begin to put in huge picture windows for the projection and viewing ports? What exactly is the point?
A-to purposely allow more chances for booth sounds to leak out.
B-to purposely allow stray booth light to illuminate the back half of the auditorium.
or
C??
 

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Posted by James R. Hammonds, Jr (Member # 673) on 12-16-2005, 01:52 PM:
 
C - To allow for additional equipment to be added at a later time (video projector for a video screening or addition of a DLP) without having to make a new hole in the wall and install another window.
 

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Posted by Brad Miller (Member # 2) on 12-16-2005, 02:59 PM:
 
D - not much of a reason, but it does provide yet another emergency exit in case of fire.

If you are purchasing quality windows and they are properly installed, A isn't a problem. Assuming your booth lighting is set up properly, B isn't a problem either. I use 2x4 flourescent fixtures to light the booth up very well and have no problems with the light from them bleeding into the auditoriums. It's all about the light directing baffles.
 

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Posted by Scott Norwood (Member # 30) on 12-16-2005, 03:23 PM:
 
I don't really like big port windows, either, but I have seen a couple of booths where it made sense. In particular, I can think of a college's screening room which contains 2 ea. 35mm projectors, 2 ea. slide projectors, a 16mm projector, a video projector, and probably other stuff that I'm forgetting right now. If they had installed individual portholes for each projector, the result would be ugly and inflexable.

For theatre use, where there would only be 1-3 projectors, I like the standard 12" square ports, and, ideally, a large followspot port off to the side with a shutter that can be left closed most of the time.
 

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Posted by Greg Mueller (Member # 17) on 12-16-2005, 03:35 PM:
 
Originally I had a smallish type port and had to open it up (pain in the butt). The reason was that the projector had motors out in front and when I set the projector back far enough for the motors to clear and allow removal of those motors, the smallish port caused vignetting when I ran scope. It's still a bit on the small side, but I had to work around studs in the wall. Looking back, I wish I had headered off a large size opening and made the port twice as big or bigger.
Probably the explanation of having a bunch of (unknown) equipment (down the road?) all trying to see out at once, sounds best to me
 

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Posted by Thomas Jonsson (Member # 1902) on 12-16-2005, 04:07 PM:
 
Didn´t the big port "era" start with Todd-AO, to allow clearence for the much larger picture?

Thomas
 

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Posted by Lindsay Morris (Member # 1430) on 12-16-2005, 05:24 PM:
 
Probably comes more from poor building design and planning and not really knowing or bothering to ask what sort of gear is going in even though most machines have a lens C/L of around 1200mm or 4 foot in old terms.
Saves building planners having to worry about projection angles and just whack in a damn big one and that fixes it
Must post some photos of a VERY carefully designed booth in Perth that depsite the best arguments by many the architect "knew best" and put all the ports in same height side by side and NO ports for the operator to look thru.
The rationale was 4 machines = 4 ports and thats it
Now the Pro 35 unit sits up on a plinth about 350 mm high which makes reaching the top feed roller very hard for shortish people.
On the odd times a 6000 footer is run almost need a ladder to get up to stick the spool on.
It all looks good from the outside but inside its a nightmare to operate.
Lindsay
 

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Posted by Bill Enos (Member # 440) on 12-16-2005, 05:56 PM:
 
Our ports were just barely adequate for scope. Last week we cut them out four inches top and bottom to accomodate 3D using the Paramount miror boxes. Ugh! what a mess, we covered everything but dust covered it all. The wall is 18 inches solid brick firewall.

The Broadstreet Cinema (demolished 10-12 yrs ago) here had glass 4 ft high and full width of the booth. An acquaintance who worked there said the AC wasn't great in the heat of summer and management required booth personnel to remain fully attired. Shirts and trousers on at all times since they were in view of the audience.
 

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Posted by Carl Martin (Member # 1146) on 12-16-2005, 06:15 PM:
 
the pacific film archive booth has a glass front wall, and it's soundproof. even during an unaccompanied silent, you can't hear the machines.

on the other hand, our chintzy ports have gaps around them and transmit a fair amount of projector clatter into the auditoria. i wish they'd be changed.

carl
 

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Posted by John Walsh (Member # 168) on 12-16-2005, 06:51 PM:
 
Many people just buy pre-made ports, and they are only made in a few sizes. Also, when people would buy both the pedestal and the projector from the same company, you could get a sheet showing where abd how big the image would be, ie: where and how big to cut the hole in the wall ... but not anymore. When you install a 30mm lens, which is fairly common now, the image gets big right away! You can just put cardboard in to block the unneeded area.
 

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Posted by Brad Allen (Member # 470) on 12-16-2005, 07:30 PM:
 
I just think that the use of the 12" port adds a little more "mystic" to the movie going experience. But that's just me.

I can remember when I was a kid (yes electricity was around) looking back up at the port holes and seeing nothing but the light of the picture and wondering what was "really" up there.

I have a young nephew that thinks the same thing. He is intrigued by the mystery of the 12" ports.
 

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Posted by Tim Reed (Member # 137) on 12-17-2005, 02:10 AM:
 
Lindsay's got it. No one designing theatres these days knows how to properly locate ports. Instead, they cut one big hole near the optical centerline and figure that'll catch anything they can throw at it.
 

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Posted by Frank Angel (Member # 248) on 12-17-2005, 06:24 AM:
 
In the first theatre I worked in in Bryan College Station, we were using Superscope anamorphots.....big, nasty things that would never actually focus. In order to one of them on the projector which was sitting very close to the front wall, I actually had to open both the projector and the view ports, grab the lens firmly in one hand and pass it OUT THE VIEW PORT, maneuver it back through the projector port back into the booth and it had to be at an 45* angle to get it into the projector port, guide it with my other hand into the projector. I always worried 1) I would drop it and kill someone in the balcony or 2) some kid in the balcony would grab the lens out of my hand when it was on outside the booth. Yah, every one is asking why we didn't just move the projector back 6in, which is all it would take; well because the ceiling had a beam running across it and the 2000ft magazine had to fit between it and the front wall. You couldn't even fit 6000ft reels. Talk about badly designed booths!
 

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Posted by Louis Bornwasser (Member # 3063) on 12-17-2005, 09:34 AM:
 
Actually I prefer the large port idea especially in a tight booth. Some adjustments in the equipment location can sometimes really help. When you are satisfied and the job is about over, then cut a mask out of masonite for the inside of the window to reduce the openings to the bare minimum. (Really helped when they added slide projectors...no work at all, just another small hole.)

Brad; agreed the booth should be off limits to all except insiders. To all others, the mechanical source of "the magic" should be protected, including even the sight of it. Ideally, it should not even come from a port, but from over the front rail of a balcony, widely diffused. Louis
 

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Posted by Randy Stankey (Member # 64) on 12-17-2005, 10:01 AM:
 
With larger ports the operator can walk down the row and quickly check the picture, theater after theater, without having to stop and look out each viewport.

When you're running 20+ machines by yourself, larger windows can be a life saver.
 

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Posted by Mark Gulbrandsen (Member # 72) on 12-17-2005, 02:09 PM:
 

quote: John Walsh

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Many people just buy pre-made ports, and they are only made in a few sizes

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Actually Kelmar will make you up any size port you want. We use a rather large port for DP-70's that they custom make for us. Porportionatly they cost us the same as the stock ports. Takes about a 60 day lead time.... typical on a large plex job.

I have seen other dealers(FROM THIS SITE ) that use pre-hung windows.... now that is really crap... and really crappy glass! They probably cost as much as the prefab ports do!

Mark
 

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Posted by Frank Angel (Member # 248) on 12-17-2005, 09:34 PM:
 
Aside from all the other problems with large ports....light spill, noise contamination, feeling like a monkey in the zoo with people gapeing at you, etc. I think the biggest problem with large ports (one theatre I work in has the front wall all glass) is that because coated optical glass is so expensive, it tempts the owner to use cheaper glass instead. Luckily in the booth I work that has the wall of glass front, they imported special optical glass from Germany and an obscene amount of money.
 

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Posted by Monte L Fullmer (Member # 2797) on 12-18-2005, 08:59 PM:
 

quote: Randy Stankey

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When you're running 20+ machines by yourself, larger windows can be a life saver

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