Threading a 35mm Projector

[Darkwing]

I know I promised to upload this 6 months ago, but I finally did upload it! This is one of the last times I ever threaded a 35mm projector before we went totally digital. As of now actually, the entire company is totally digital and I imagine by the end of this year, our major competitor will have completed their digital conversion as well. So in fact, probably 90% or more of Canadian theatres will be totally digital. Kind of significant if you ask me seeing as film of one form or another was how movies were projected for nearly 100 years. And I'm gonna admit it, though the digitals save a lot of troubles and problems with projection, I actually quite miss my film!

 

 

Oh, and please don't share this, I dunno how the company i work for would respond if they ever found out...

[robcat2075]

Cool. I had never actually seen the large platters those wind on. But how does the film come out of the center of a reel?

[Rodney]

Very cool. Thanks for sharing.

 

It looks like you'd done that a few times!

[Darkwing]

Cool. I had never actually seen the large platters those wind on. But how does the film come out of the center of a reel?

 

There's a device in the center called a brain. It feeds the film through and then up to the first roller. I'll draw it for you tomorrow or something as I don't have a picture of one. Though come to think of it, we might still have some brains left in the booth so maybe i'll take a pic if I can find one. The term Brain Wrap is when it fails to do its job properly and the film literally starts wrapping around (or sometimes in a mound over) the brain. Fixing that can be tricky and can range from a simple 2 minute fix, to cancelling a show because it's gonna take half an hour!

 

 

Very cool. Thanks for sharing.

 

It looks like you'd done that a few times!

 

For two years I think! When I first started, it took about 7-8 minutes. By the time we went digital, I could do it in under 2!

[robcat2075]

Hey, I got a projector question...

 

Last month I saw the most the most stunning film presentation I'll ever see in my life, the 1927 "Napoleon".

 

It was all on film of course and the last two "reels" were a three-projector explosion like this:

 

 

 

however... At the beginning of the film the projectionist appeared to be making an adjustment on-the-fly that seemed to be a choice between a very bright image with severe flicker and a less bright image without serious flicker. After about five minutes he settled for less-bright.

 

What was he doing? Is there some way to change the number of blades in the shutter while the film is running?

[Darkwing]

Well, I can only speak from the model project we used (a Strong X90 or something like that) and they were really fairly basic in terms of extra functionality. A cinema like the one you've posted probably has bells and whistles. So speaking from our projectors, there's no way to change the shutter and really, the flicker is going to occur 24 times per second anyways (unless it's a different frame rated projector, which I doubt seeing as 35mm I think are all 24fps. Imax is probably different though, but those are whole different projectors anyways.) The only way for changing the brightness that I know of, is to adjust the reflector. See when the bulb emits light, that's not what's really being projected. There's a large sort of half dome behind the bulb which reflects the light forwards to the lens and onto the screen. Adjusting the distance of the reflector from the bulb will increase or decrease brightness. Also, in the process, it will either focus or widen the spread of light. Focusing the light is bad as it has a tendency to shatter the lens. That said, if the light is more focused (which generally results in a bright spot in the center and a dull vignette on the edges). I have noticed that the brighter and more focused the light, the more prominent the flicker, so it's possible the projectionist was altering the reflector and as it got dimmer, the flicker became less pronounced. But that's really only a guess, like I said, projectors have their own quirks and personalities.

[largento]

A film from that era would have been handcranked, so it's hard to know what the actual frame rate was and it wouldn't have been entirely consistent. Perhaps he was attempting to compensate for that?

[robcat2075]

So speaking from our projectors, there's no way to change the shutter and really, the flicker is going to occur 24 times per second anyways (unless it's a different frame rated projector, which I doubt seeing as 35mm I think are all 24fps.

 

Part of the aura of this presentation was that they were showing it at the original frame rate of 20fps so they must have had something unusual there.

 

They built two extra projection booths in the theater to handle the format and the fire department made them redo it all the day before the show. Ouch.

 

 

I've read there are two bladed shutters to make two blinks per frame and three bladed shutters because two isn't really enough to hide the flicker but i figured it was something you'd need to manually switch out if they could be switched at all.

[Darkwing]

I agree. I'm not sure when this started, but I know it's pretty standard for a projector to only play 24fps. That said, it really does sound like there was some sort of special set-up. Again, I can only speak from ours and we never had any sort of functional control over the shutter. You probably know this, but the most basic principle behind it is that while the intermittent sprocket turns, the shutter is closed. When the sprocket stays still for 1/24 of a second, the shutter is open and so on and so forth. Again, that's the very basic concept behind it and I would imagine larger, more impressive projectors have more more control over these sort of elements.