Film-Tech Forum ARCHIVE: Fim loading the night before

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Posted by Daniel W. Skeen (Member # 4269) on 09-23-2007, 07:30 PM:

What are the pro's and con's to loading movies the night before. I have some people say it's okay, I have some people say it's not good for the film or the machines. That would leave them loaded and sitting idle over a 12 hour period.

Posted by Chris Slycord (Member # 4239) on 09-23-2007, 08:23 PM:

Wherever you have a roller inside the projector that has a locking mechanism holding the film in place will have it's springs at full tension for the entire time. This can be especially hard on various sound head models.

Also, there's the issue of dust collection (a lot of people want prints covered overnight).

You'd have to make sure to not engage your platter tension mechanism otherwise that too would be engaged for 12 hours uselessly but if you do that then the clear leader will sit on the floor for the same amount of time.

Posted by Mike Blakesley (Member # 26) on 09-23-2007, 09:04 PM:

This has been debated here before, I think. The issue of springs is a non-issue because it's been recommended here that you not open your pad rollers during the night.

There's the issue of the film being "stressed" by being wrapped around rollers, sprockets and such over night, but since most of what's threaded should be leader, that's not really an issue.

The only real concern is the one of dust collecting on the sections of the print that are strung thru the air. You could get around most of that problem by having a clean booth.

Posted by Mark Gulbrandsen (Member # 72) on 09-23-2007, 09:27 PM:

I was taught to leave the gate open at the end of the day. This releases the pressure on all the gate springs/bands and helps keep the springs from getting compression set. Bands can also stretch somewhat. As for pad rollers its the same reason... if your pad roller springs are not compressed in the closed position then leave them closed... if not in the open position then leave them open. You won't be placing any more wear on these mechanisms at all since they'd have to be opened to re-thread the machine anyway the next day. But overall following the above will help keep springs in spec. for longer periods.

Mark

Posted by John Hawkinson (Member # 1135) on 09-23-2007, 10:36 PM:

...and here I thought we were talking about cameras [Smile]

--jhawk

Posted by Scott D. Neff (Member # 185) on 09-24-2007, 03:43 PM:

quote: John Hawkinson
...and here I thought we were talking about cameras

What website have you been smoking? [Razz]

Posted by Gordon McLeod (Member # 33) on 09-24-2007, 04:23 PM:

If the pinch roller in the soundhead is left closed and non rotating it will develop a flat spot introducing wow and flutter

[ 09-24-2007, 06:09 PM: Message edited by: Gordon McLeod ]

Posted by Tim Reed (Member # 137) on 09-24-2007, 07:35 PM:

Please leave them un-threaded. When I come in for a service call, I'll just un-thread them anyway. [Wink]

Posted by Ken Lackner (Member # 1002) on 09-24-2007, 08:21 PM:

quote: Tim Reed
When I come in for a service call, I'll just un-thread them anyway.

Word.

Posted by Don Furr (Member # 1469) on 09-24-2007, 08:52 PM:

Like Mark, I was taught back in the 60's to always open the gates and all pad rollers. I never questioned it.....just did it and STILL do it. Probably not as important as I was led to believe it was.

Posted by Bryan M. Montgomery (Member # 4412) on 09-25-2007, 12:22 AM:

John was refering to the threading of the equipment being refered to as "loading," like you load a camera.
It was a joke y'all, catch up.
One big thing I have against overnight threading is the large number of poorly trained personnel operating booth equipment all over the country, imagine the button-pusher failing to notice the film that the HVAC blew off a vital roller the previous night, and just fires her up and walks away.
Can you say film damage?

Posted by Chris Slycord (Member # 4239) on 09-25-2007, 02:56 AM:

On the other hand, you'd trust them to thread the movie instead? If they suck as bad as your not-so-hypothetical person does, they're gonna suck all the time; not just when pushing the button for a show someone else threaded.

Posted by Robert E. Allen (Member # 1351) on 09-25-2007, 03:45 AM:

There is no justification for threading the machines the night before. If the person starting the machines does not have the time to clean and thread the machines or is not well trained enought to do anything other than press a start button then they have no business being in the booth.

Posted by Phil Blake (Member # 2012) on 09-25-2007, 09:26 AM:

I always leave the machines empty at the end of the day.
Before I thread for the next day I always like to run the machines for a 5 minute "warm up" before threading.

I don't like running them with film "cold" on their first run of the day.

Posted by Chad M Calpito (Member # 3736) on 09-25-2007, 09:46 AM:

I like to leave the machines unthreaded over-night. There is no need to have them ready and just sit there doing nothing. Besides, I like to do my maintenance work on the equipment before I thread the machines up.

Posted by Louis Bornwasser (Member # 3063) on 09-25-2007, 09:57 AM:

Robert: you are exactly right.

Expectations are low therefore the result is low.

Other than dirt buildup, there is no practical difference if film is threaded "early." Compared to the wear of threading each and every 20 minute reel, ewuipment now gets a free ride. The exception is the "set" film gets from being stopped in the gate/rollers. Evenso this only affects the leader. Louis

Posted by Gerard S. Cohen (Member # 994) on 09-25-2007, 12:34 PM:

In my experience, management decreed the projectors be threaded up the night before when they were pressuring the unions to replace their projectionists with non-union employees hired by the managers at much lower wages.

They were trying to establish a pattern that anyone could start a show in the face of a work stoppage, and that "projectionists" were obsolete. Some chains forbad the term itself as they combined the duties of janitor, usher, porter, doorman, concessionist and booth attendant into one interchangeable minimum-wage (or less) employee.

It was easier to teach the rookie to push the start button than to teach him or her to thread up--many never learned to even set the intermittant. This enabled chains, managers and assistants to pretend projection was not a skilled craft and led the downward slide to mediocrity.

Posted by Mark Gulbrandsen (Member # 72) on 09-25-2007, 02:43 PM:

quote: Phil Blake
Before I thread for the next day I always like to run the machines for a 5 minute "warm up" before threading.

This is the absolute best reason I've read here for not threading up the night before... Indeed running the machine for a few minutes is a huge advantage to getting extra life out of the intermittent, bushings and gear train. Most movements oil drains back out of the parts that require them and pre-running the machine places oil back where its needed most... same for an all oil bath machine... for cushioning on the star/cam radius and on the cam pin as well as every gear pair.

Also its best to leave the cam pin just disengauged from the star's slot at start up... this allows almost one complete revolutuon of the gear train and more time for the mechanism to come up to speed before a load is placed on the pin and star itself.

quote: Gerard S. Cohen
This enabled chains, managers and assistants to pretend projection was not a skilled craft and led the downward slide to mediocrity.

Sorry Gerard... not totally true... while there were many very good IA locals some locations locals were so bad that in many cases the rookies were way beyond the operators capability.

Mark

Posted by Ken Lackner (Member # 1002) on 09-25-2007, 05:40 PM:

Forgive the ignorance here, but what difference does it make whether the machine runs with or without film? I have never heard of this before.

(I am NOT advocating threading the night before, I just never heard of this as one of the reasons for not doing so.)

Posted by Steve Guttag (Member # 268) on 09-25-2007, 08:17 PM:

This has been discussed before...but the jist is...lubricants are stiffer when cold and they tend to pool at the bottom...which means that all of the bearings, gears and even the intermittent are not evenly lubricated after things have been at rest for a long while (overnight as opposed to between shows/reels).

Spin a projector over by hand at the beginning of the day...run the projector for 5-10minutes and then spin it over by hand...you should almost always feel it spin more fee after it has warmed up.

Having the film in the projector makes everything work harder (wear more) when it isn't at operating temp.

Steve

Posted by Richard May (Member # 2627) on 09-25-2007, 09:20 PM:

I definitely have done that and do notice that it runs smoother after warming up. I'm just wondering whether it really matters. I'm not talking about threading the night before because I never do that. I have been at the same theater for more than 17 years. We never warm up the machines. I have never had to replace any bearings related to the drive train. The intermittents are still running perfectly too. So I'm not sure it's such a big deal to run the machines before the first show.

Posted by Tim Rectanus (Member # 3282) on 09-25-2007, 09:43 PM:

My question now is not what the problems are with threading up the night before but what the advantages are. I mean, are you really getting there late enough that you don't have 3-7 minutes to thread up the projector? That is the only decent reason I could think of for threading the night before, time. I think we all try to get things done with the least amount of work and energy but that is a new kind of lazy. Maybe it is different with other systems but our SR takes very little time to actaully thread up.

In case you couldn't tell, we don't thread up the night before at my theatre. In the morning we test the moving parts of the projectors (FFs, Dowsers, Rotors, and the such) using the cleaning mode and run it for a bit to get things warmed up, without film.

Posted by Bryan M. Montgomery (Member # 4412) on 09-25-2007, 10:06 PM:

No Chris, I dont trust them, I train them the very best I can, given the very limited time the "people downstairs" give me, and off they go. The budget and the operators willingness to do a good job dictate what happens when they run the booth, and we have very little of either, so I try to limit the damage they can do, and one way is to not allow overnight threading.

Posted by Mike Blakesley (Member # 26) on 09-25-2007, 10:14 PM:

quote: Richard May
I definitely have done that and do notice that it runs smoother after warming up. I'm just wondering whether it really matters.

I don't run the machine before threading, but it would be a simple matter to flip on the motor switch, then go move the platter ring, thread the film past the projector and back to the platter, and then shut off the motor and thread the projector. It's not a five minute warmup but it would be better than nothing. I agree with Steve about how the machine runs better after warming up.

Posted by Richard May (Member # 2627) on 09-25-2007, 10:21 PM:

I'm not saying they don't run smoother. I did say that they do. My point is, I don't think any wear is being caused by not warming them up before threading.

Posted by Mark Gulbrandsen (Member # 72) on 09-25-2007, 10:43 PM:

quote: Richard May
I don't think any wear is being caused by not warming them up before threading.

Actually alot of wear is happenning at that time if threaded with film. Just like starting your car on a cold morning and putting it in drive about 5 seconds later then another 5 seconds later going 60 mph down the freeway with out the temp gauge having budged... the lubricants haven't had a chance to begin working(unless you're using syntthetics)! If you know know of one have a local mechanical engineer calculate the tons of force that are on the cam pin when its moving film vs. when its not vs. the added cushion of oil on both the pin and radius, ditto for the bushings. Oil makes a huge difference.

What I generally go by is running something like an X-L for a long enough time for oil to come out the back side overflow hole on the movement as sufficient time to re-distribute the lubricant, typically a minute or two. On a DP-70 until the oil overflow pipe on the movement is flowing, etc. A Century only need run for 30 seconds or so to distribute what little oil there is. In the latter instance synthetic oil can double the life span of a Century movement. With Phillips FP-20 and similar(Ballantyne) there is no real need to pre-run the machine because all the precision stuff is totally submerged in oil.

The most important thing is that a cushion of oil be present on all moving parts before the added force of pulling film begins.

Mark

Posted by Chris Slycord (Member # 4239) on 09-25-2007, 11:18 PM:

The only reason to do this would be it saving one of time or money. It does neither from what I see.

If I'm threading because in the morning I'll be tired and won't want to thread, I'll be tired because I stayed late threading.

If it's to save $ paying the morning guy, the savings is offset by the extra hours spent by the operator the night before.

Posted by John Wilson (Member # 269) on 09-25-2007, 11:59 PM:

quote: Tim Rectanus
I mean, are you really getting there late enough that you don't have 3-7 minutes to thread up the projector? That is the only decent reason I could think of for threading the night before, time.

But multiply those 3-7 minutes by the amount of screens and you can start to see it eats up a fair amount of time. With ten screens you now have spent the better part of 40 minutes threading up when it could have been done as they finish the night before leaving you time to do some maintenance around the cinema.

Posted by Thomas Pitt (Member # 4322) on 09-26-2007, 12:24 AM:

What about putting 5 minutes worth of 'scrap' film (old trailers, scratched movie film, threading leader etc) on the beginning of the platter? Then you could thread it up the previous night, and the only parts of the film exposed to airborne dust and dirt would be the scrap film.

Then, simply program the start timer 5 minutes before the advertised feature start time. This will allow all this scrap film to run through, and get the projector warmed up. Use an additional cue so that the 'show' doesn't start (lamp strike, douser open, auditorium lighting down) until the head leader is going through the projector, then it will run the show as normal.

What are your thoughts on this suggestion?

Posted by Monte L Fullmer (Member # 2797) on 09-26-2007, 12:41 AM:

quote: Thomas Pitt
What about putting 5 minutes worth of 'scrap' film (old trailers, scratched movie film, threading leader etc) on the beginning of the platter?

When I used to work for MANN THEATRES back in the early 80's, we used to have a 5 min chunk of film on the beginning that was called 'canned presentations' - all it was was music with a swirly imagry that would be attached and presented before feature..and we would start our performances 5min early for this added presentation...and what a pain to remember to start our sets early.

(Also, if running machines empty for warmup, please open your intermittent shoe assembly, so that the metal to metal contact aint wearing out both the shoe and sprocket surfaces).

I've never been a fan for lacing up the night before for many reasons previously mentioned-both mechanical and human reasons. The human side, esp with dealing with high school kids, is that if you lace up a house the night before and the first start of the next day goes wrong, you know where the finger can be easilly pointed and who would rat on the mgr for this mistart..

Leave a machine empty and the finger has nowhere to be pointed at except at the booth clown who laced the machine.

Posted by James Westbrook (Member # 3690) on 09-26-2007, 12:59 AM:

"Canned Presentations".
I walked into a showing of Tarzan The Ape Man (The Bo Derek one) when the music psychedelica thing was on screen. That gave me a WTF moment...later, the movie itself made me wish I was at home doing...laundry or something less surreal than...that.
Anyway, do you remember the psychedelic Coming Soon or Now Showing or (this is on the beginning of the Kill Bill 1 DVD) Our Feature Presentation? I had one of my buddies visiting at the UA theatre and one of those was through the brains of the platter (this was during intermission) and my bud saw it and remarked "Oh NO! You aren't running those crappy music things like Mann Theatres have too, are you? I HATE those things!"

Posted by Brad Allen (Member # 470) on 09-26-2007, 01:45 PM:

So, should synthetic oil be used in say Simplex 35 projectors instead of Simplex Oil?

Posted by Louis Bornwasser (Member # 3063) on 09-26-2007, 02:36 PM:

ANYTHING is better than Simplex oil.....10% varnish. Louis

Posted by Mark Gulbrandsen (Member # 72) on 09-26-2007, 04:20 PM:

quote: Brad Allen
So, should synthetic oil be used in say Simplex 35 projectors instead of Simplex Oil?

If you want to yes. Just be sure to get something thats close to Simplex oil in viscosity. They don't use SAE on synthetics. Synthetic compressor oil would be a good choice... Strong actually had considered doing a synthetic fill on new Apogees at the factory and reccomending a once a year change
But like most things at Strong that was only a thought.... [Eek!]

Mark

Posted by Paul Van Dusen (Member # 3640) on 09-28-2007, 10:37 AM:

quote: Tim Rectanus

My question now is not what the problems are with threading up the night before but what the advantages are. I mean, are you really getting there late enough that you don't have 3-7 minutes to thread up the projector? That is the only decent reason I could think of for threading the night before, time. I think we all try to get things done with the least amount of work and energy but that is a new kind of lazy. Maybe it is different with other systems but our SR takes very little time to actaully thread up.

Ok, I'll admit it, we thread the night before at my theatre, but only on the weekdays. And we have a pretty good reason in my opinion. Mon-Thurs it's just one employee in concessions, and me or my assistant in the box office/starting movies. By the time I get all the money counted and everything else set up to open, customers are arriving and I have to sell tickets. By the time I get the chance to run upstairs I have enough time to turn on the projectors & sound towers, double check my assistant's threading and hit start.

Posted by Chris Slycord (Member # 4239) on 09-28-2007, 12:25 PM:

So the "good reason" is a lack of proper planning?

And money wise, you aren't saving anything by having a guy stay later threading just to save money by not having someone come earlier in the morning.

Posted by John Wilson (Member # 269) on 09-28-2007, 09:36 PM:

He shouldn't stay later, just re-thread what finishes first at end of night. The last one or two to drop stay unthreaded.

Posted by Michael Cunningham (Member # 210) on 09-30-2007, 02:28 AM:

I dunno, back when I was grinding in a booth, I always had to be there early anyway. When do you : clean screens, clean house vents, clean amp racks (behind screens), do complete projector cleaning (noisy air compressor), drag your ladder into houses to clean ports, vaccuum the booth (also noisy), change oil or belts, etc.? All that stuff that requires hours of daily time but can't be done during show hours?

If our first show was at noon, I always had to be there by 9 anyway so plenty of time for threading as I went along. Not that this is a complaint against threading at night, but it doesn't seem like a time saver to me.

Posted by Mike Blakesley (Member # 26) on 09-30-2007, 08:24 PM:

Michael - you must remember that at a whole lot of places they don't do any of the items on your list.

Posted by Frank Angel (Member # 248) on 10-01-2007, 06:14 AM:

I was taught both things: 1) warm up your machines sans film -- with that same reason given about getting oil moving (and that was decades ago), and 2) leave all the spring-loaded parts opened (or "relaxed"). The latter, except for the pressure roller on the drum which can develope flats, I think is much over blown. I mean, those springs are engaged all day long when the projector is running, no? How come that doesn't negatively affect the springs? Be that as it may, I still follow old habits and "unspring" everything at night.

And we never thread-up the night before. Just come in on time, damnit--which means enough time to thread your machines!

Posted by Ken Lackner (Member # 1002) on 10-01-2007, 08:04 AM:

I am not advocating threading the night before, but I know that the reason some theaters do it is not to save money by having the operator come in later, but in case the operator doesn't show (and don't start saying they should hire more responsible people who will show up on time; anyone can get in a car accident or something like that), the manager can head upstairs and start shows.

Posted by Chris Slycord (Member # 4239) on 10-01-2007, 10:00 AM:

If your operator regularly doesn't show and you must thread early for this... maybe you should be firing his/her ass.

Posted by John Walsh (Member # 168) on 10-01-2007, 10:40 AM:

Some people (not everyone) are assuming there are 'projectionists' at theaters. My experience is when there are 12 screens or less, there isn't any; the manager must handle it, usually sending ushers /concession staff up to do it.

If other things are well-run, I'd say OK; you've got to pick the battles.

Posted by Ken Lackner (Member # 1002) on 10-01-2007, 10:44 AM:

Dude, did I not JUST say that I'm not talking about irresponsible people not showing? I'm talking about someone not showing due to a car accident or other unforseen occurence. It can happen to anyone.

Posted by Brad Miller (Member # 2) on 10-01-2007, 05:54 PM:

quote: Frank Angel
The latter, except for the pressure roller on the drum which can develope flats, I think is much over blown. I mean, those springs are engaged all day long when the projector is running, no? How come that doesn't negatively affect the springs?

Nobody is worried about the pressure roller's spring. They are saying that when the pressure roller is sitting in the clamped position on the sound drum and it is NOT spinning, that flat spots develop.

That's not a myth, it is reality. (It is also a retarded soundhead design, but that argument can be saved for another day.)

Remember though, every projector is different as to what parts should be reopened at night and what parts should be left closed in the "running" position. Personally, other than the stupid Simplex/RCA/boatanchor soundheads out there, I've not found any issues over time with just leaving everything closed at night after the tail runs out.

Posted by Ken Lackner (Member # 1002) on 10-01-2007, 09:12 PM:

I was under the impression that the gate should be left open on any projector that uses tention bands -- Christie, Simplex, Century, etc.... Never heard anything about leaving the pad rollers open or closed due to tension on the springs. But I would leave everything open anyway because I would clean every machine as I shut them down.

Posted by Scott Norwood (Member # 30) on 10-01-2007, 09:17 PM:

I'm a big believer in leaving Century gates closed overnight. If they are left open, the gate springs wear out prematurely. For the same reason, I leave Simplex gates closed as well, though I haven't had to replace a Simplex gate spring.

At one point, I think that Gordon recommended removing the gate (or trap) to eliminate wear on the bands, which seems like the ideal situation, though I've never seen it done in practice.

Normally, I leave pad rollers and Simplex/RCA sound rollers open and everything else closed on Century and Simplex heads. With Kinoton, I just leave everything as-is (i.e. closed) overnight.

I would be curious to know if the manufacturers have any thoughts on what should be left open or closed overnight. Does anyone actually remove lenses from the projectors overnight (presumably to store them in a cabinet or other location protected from dust)? I've seen this recommended before, but have never seen it done in practice.

I don't generally clean projectors at the end of the night if they will be run again the next day. I think of this as something that should be done before every show. I do clean the machines thoroughly if they will sit for some time before the next show (as in venues that aren't full-time theatres).

Posted by Floyd Justin Newton (Member # 1316) on 10-01-2007, 10:10 PM:

Scott-- At the orignal Cine Capri we removed the gates AND lens from the machines (JJ3) at the conclusion of the last performance. This releaved any possibility of the bands having any pressure on them. The lens were stored in the lens cabinet.
Sad to say the Cine Capri was the last true movie theatre in
Phoenix. It was demolished to make way for an office building.
Nothing but cracker boxes here now. [Frown]

Posted by Paul Van Dusen (Member # 3640) on 10-01-2007, 10:46 PM:

quote: John Wilson
He shouldn't stay later, just re-thread what finishes first at end of night. The last one or two to drop stay unthreaded.

That's pretty much what I tell my assistant to do, although that's not always the case. The boy loves to ride my clock.

quote: Michael Cunningham
I dunno, back when I was grinding in a booth, I always had to be there early anyway. When do you : clean screens, clean house vents, clean amp racks (behind screens), do complete projector cleaning (noisy air compressor), drag your ladder into houses to clean ports, vaccuum the booth (also noisy), change oil or belts, etc.? All that stuff that requires hours of daily time but can't be done during show hours?

All that stuff gets done during our office hours from 10-12 every weekday. Your also assuming i'm a projectionist, i'm the theatre manager. I've got so much crap that i have to cram in the average day, having the projectors threaded for me is just one less thing i have to worry about. Besides, as i said in my original post, it allows me time to run the box office, open the theatre, count the money, etc. Your average projectionist doesn't have to do any of this extra managerial stuff.

Posted by John Hawkinson (Member # 1135) on 10-01-2007, 10:53 PM:

Scott: We remove our lenses from our Century Cs and toss in our Kollmorgen bottleglass lenses (Academy ratio) at the end of every night. We also clean the trap rails (excuse me, gate pads) at the end of every night (as well as the beginning).

--jhawk

Posted by Kurt Zupin (Member # 2751) on 10-01-2007, 11:05 PM:

Floyd-

Have you been to our new theatre? The new Cine Capri? Thats the theatre I'm a manager at.

Back on subject. We open all our film gates and turrents at the end of every night. And I wouldn't ever thread up night before. not to say I havn't done it before. At my old theatre back in Michigan when I would close and then open up the next day I would thread up before leaving. This is because, I worked a second job from 3am to 9am. So if I knew I was the one coming in in the morning then I would do this.

Posted by Frank Angel (Member # 248) on 10-02-2007, 03:49 AM:

quote:
The latter, except for the pressure roller on the drum which can develope flats,

Brad, that's what I said. What I was questioning was about the springs and the bands. I am not saying that the tension won't be reduced a bit over time, but my contention is that such a reduction would be so minute as to be insignificent that people need not get paranoid about it if they did or did not leave the gate closed. So the bands last 9.5 years instead of 10 -- miniscule enough that I am not going to turn the car around and head back to the booth to make sure I left the gate opened, is what I meant.

Posted by Brad Miller (Member # 2) on 10-02-2007, 05:13 AM:

Aha, I gotcha. I had misread what you wrote.

Posted by Steve Guttag (Member # 268) on 10-02-2007, 06:23 AM:

Over time, I have had more issues with gate closing springs loosing tension (Simplex/Century) than tension bands loosing tension. In fact, since polyester prints have become the norm...having tension bands wear out has been a greater wear factor than loosing tension.

I have therefore always left my gates closed at night and pad rollers in their most relaxed state. If the springs are of equivalent tension open or closed, I'll leave the pad roller open after cleaning.

Steve

Posted by Stephen Furley (Member # 1277) on 10-02-2007, 08:08 AM:

quote: Scott Norwood
Does anyone actually remove lenses from the projectors overnight (presumably to store them in a cabinet or other location protected from dust)? I've seen this recommended before, but have never seen it done in practice.

I would guess that most people with turrets leave the lenses in, as they are pretty much a semi-permanent part of the projector in that case, while those with single lens holders probably take them out at the end of the day and return them to the cabinet, as the lenses are frequently being removed to change format anyway. I've only ever used single lens systems, but I can't think of anywhere, other than one occasional venue, where it wasn't normal to remove the lenses at the end of the day. I also remove the aperture plates. As for gates, it seems to vary, some places leave them open, some closed, and a few remove them; I've never found it to make much difference. I generally tend to leave them open, probably because I always open them as soon as the film comes off to check for any sign of problems, excessive build-up of dust, emulsion, or overheating, for example. Once it's open I tend to leave it that way.

I check the lenses before mounting them, but don't normally clean them; I aviod cleaning lenses unless they're actually dirty.

Most places that have, or had, 16mm machines seem to leave the lenses in on those; I don't know why the difference.

On the digital projector, of course, the lens stays in. The manual mentions a lens cap, but I've never seen one. Did other DSN venues get a lens cap with their machines? Did AA remove them because people were forgetting to take them off, and melting them?

Posted by Joel N. Weber II (Member # 3530) on 10-05-2007, 12:30 AM:

quote: John Hawkinson
We also clean the trap rails (excuse me, gate pads) at the end of every night (as well as the beginning).

At least as of a few years ago, that was highly dependent on who was projecting.