Thanks

Richard
 

The 20 feet is to reach from the failsafe to the platter's takeup ring.

The 10 feet of framing leader is obviously to thread on.

The 40 feet clear is enough to ensure that if the show is started with the curtains open, there will be enough time for the curtains to close before the actual "start" cue goes through the machine, which is placed at the start of the black. This stretch of leader also guarantees the start of the first trailer does not get damaged from airborne dust as well as providing an "abort" possibility.

The 10 feet of black is used to ensure the douser will always open ON BLACK. For standard 7 second douser automations, if the douser dies, the black leader can be motored down to the first foot of it and the show can be started on the timer as normal without having to use the manual douser (great for timers).

This also saves significant $$$ on leader costs, as the clear non-frameline leader is very, very cheap and comprises the majority of the leader.

-Mike
 

I recall from another thread that triacetate is a good idea for tail leader, in case the last few laps jam on the platter. But what about for head leader (threading and framing)?

Do people prefer leaders that are about as stiff as the print itself, or do you prefer really "stiff" (i.e., thicker) leader for durability?

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John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Eastman Kodak Company
Research Labs, Building 69, Room 7419
Rochester, New York, 14650-1922 USA
Tel: 716-477-5325 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com
 

The tail leader should NEVER be made of polyester but yes: even the head leader should be triacetate. As for the thickness of a leader, I'd prefer to not have them too stiff. Proper care of the equipment and an unhurried, careful threading should be enough to increase their durability in any case.

A good alternative for making up the heads as I described above is to replace the last 10 feet of the 40 foot clear stretch with a stretch of acetate. That way if there is a misthread, it will just snap and drop the failsafes.

I NEVER use polyester leader for tails. First off it is too stiff and has a tendency for a tuck to go flying out from under the print. Second, generally if the film is going to tangle, it will be in the last few rounds. I have always added 30 feet of acetate clear tail as standard practice and it has saved me much grief over the years. It also keeps the end of the credits nice and perfect.

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Bob Throop
 

You mentioned that you don't use polyester leaders. Well aren't all films made of polyester these days so? So if I was making my own home made leaders from old trailers, they would be made up of polyester segments. So then is it worth the time and effort to do such a thing if polyester is so bad, or just put out the money (which of course will never be there).

Richard
 

But we really don't have much of a choice anymore, now that acetate has virtually disappeared. Most of the head leaders I use are nicked from the front of trailers and they're all poly.

The stronger stock is probably a good idea as the leader is the section of film which has to absorb the strain caused by the projector mechanism accelerating from stationary to 1 1/2 ft per sec.
 

I triple check my threading, spin the projector motor immediately before pressing its power button, and I give the platter disks a gentle push. I've never had a problem except for one back in 1985. I was new to the Christie projector of that day. Somehow, two or three times, I threaded so that on startup the gate popped open. But there was no damage, not even stretched mylar, so there was no need for triacetate's breakaway ability.

One note on spinning the projector motor and the platter disks. This both makes those motors and drive trains last longer and it acts as another check on my threading. If something's wrong, I will spot it more quickly in the process of doing these things.

The trick to getting a perfect show start is simply total concentration. If someone tries to interrupt me, I simply answer them like a zombie. They just can't get into my mental space. Now if only I had this ability when it comes to one of the administrators I have to deal with!

I like how indestructable mylar is for leaders. A film festival we hosted left us some of their extra. This stuff looks like it put in some time on a dance floor, a rodeo arena, or someone's driveway, and it still runs smoothly thru the projector. But mylar vibrates very differently from film. I "tune" my loops. If I am working a projector I don't know, I run shows with loops of different sizes to find the exact position that is the smoothest. Of course, you can never judge that by the mylar!

As for comments on tails, you all are not kidding. I'm the manager-operator for a small art house and we get the whole gamut of film conditions. I've seen a catalog's worth of strange things. It seems to me there's a fifty percent chance if something weird is wrong in a print, it's wrong somewhere between the middle of the credits and the last sprocket hole. But all I do is check whatever's on the print.

What I am wondering is how much time many of you can actually devote to startup? If you are running a large multiplex with a demanding schedule, it seems to me some of you are being asked to work so that you don't have time to do anything but press the button and run to the next projector at showtime. Of course, I've heard stories about places where that button is pressed from a remote location.