I like a seperate projector porthole and observation port. The projector port should be 12" by 12". Same for the observation port.
I like to turn on some lights in the booth to see what I'm doing without having lights shine out into the auditorium and bothering everyone.

What's everyone's preference?
 

In the carbon days (here in my state) the law was: no port will be larger than 144 sq inches. At an old theater we had, the port was 12" square. But when we twined it, we needed a much shorter focal length lens, so we had to shim the projector height high enough to fit the image through.
 

But, seriously, I work in a house that has 12 x 12 ports with seprate viewport. It's fine with me. The house was built with changeover and has two port/view combos, and both are open and uncovered. I have to watch about the booth lighting so it doesn't bother patrons when I'm in the booth.
 

I think the port size should be in harmony with the image going through it. If a 12x12 does it, fine, then 15x20 or 18x18 should cover just about any of the rest. The view ports, which I think should be separate, should be 12x12.

Projection ports should be on _CLEAR_ coated glass (particularly if it is of the new double glass design)

As to the light in the booth. Most booths are put in nowadays with florescent fixtures which just aren't needed or desirable. The projection equipment should be lit with "bullet" fixtures that can be aimed to the work area, not the audience. Any wall behind a port should be painted BLACK. The overhead lighting should either be down-light or even better, indirect and reflected off the cieling so you have plenty of light in the work area and none going out the ports (except for the projection beam, hopefully).

The front walls of the booth (providing that there isn't a set of ports on the other side) can be painted a bright color to help with lighting.

Steve
 

But, since in much of the world it seems as if the last thing many projectionists do is look at the screen, why isn't there a move to make the ports larger so the operator can easily see the screen to check for picture quality. I know they are supposed to, but I've been in so many theatres that the film has come up in the wrong format, out of frame or out of focus, it seems that if there is anything that can be done to get operators to look at the screen it should be employed. Work lights can be designed to reduce pollution into the auditorium and glass can be properly fitted to reduce noise pollution.

Look at it this way, when you're driving a vehicle, the larger the windshield, the better your vision. Don't smaller ports simply turn an operator inward and make him/her even less aware of the world outside? If ports were larger as a standard, operators would have to be more careful and aware of the audience.

I'm not talking about the "Brad Miller Level of Attention," I'm talking about the other 90% of America's screens.
 

The Telluride Film Festival has big port glass because there could be a wide variety of formats shown. Let's see, in the last 3 years, the Festival has shown 16mm, 35mm, 35mm double system, 35mm two projector 3D, 70mm, 70mm two projector 3D, video with the Digital Projection 8GV, Video with the projector hung on the basket ball bracket, slides and some sort of 18th century oil lit glass plate slide thingy. Did I miss anything?

New slogan for next years tech T-shirt.

Vespucci Pictures Tech Crew,
We change film formats more often than we change our underwear.

It makes a lot of sense to have the large port glass. I noticed in the new Chuck Jones Cinema that you purchased a 7' long optically perfect sheet of glass. I heard it cost 7 large. It looks great. I know that at the festival we spend a lot of time chasing down all stray light. As evidence look at all the cardboard that I have taped on to the projectors at Minnie.

The large port glass may be beneficial when theatres start the transition to electronic cinema. But that would be an infinitesimal cost saving.

I prefer to have two small projection ports for all the reasons Joe mentioned. It is good to be able to turn on the lights in a commercial booth in order to troubleshoot.

In the theatre that I am about to take over, there are small ports that are home made. You know the type; they are two pieces of ½ x ½ inch wood strips in which glass from the hardware store has been slid. The glass is scratched and there is a half-inch gap between the glass and the top of the frame. I am sure you can hear the projectors out in the auditoriums. I'll just have to add new port windows to the list of improvements we are going to have to make.

 

If you don't like light pollution, you can go downstairs to the lobby and 'appropriate' a couple of those red tubes for the fluorescent lights. We have one house where the fluorescent hallway light shines into the theatre and that's what we did. It works pretty well.

All of our proj. have a fluorescent light overhead and a 'can' light pointing to the proj. head. We can pull the chain and have the can turned on without the fluo. Of course we turn out both lights during the show. Only the hall light (recessed cans) stays on. We don't have much problem with stray light. (Except for the one I mentioned.)
 

Aaron