Doing a changeover

[Adam Liberman]

Could someone please explain to me the details of doing a changeover? I have run 35mm projectors, but in a sound mixing studio setting and not doing changeovers.

What frames are the motor and changeover cues placed on?
What frame is the incoming projector threaded on? I assume that this needs to account for reaction time and motor run-up time.
Are there any automation cue reader systems to do changeovers, or only for automating platter systems?
Thanks!

[Dave Macaulay]

There are two leaders, SMPTE and the other one ("academy" leader?). The numbering is a bit different but regardless "PICTURE START" is 8 seconds (192 frames at 24fps) ahead of the actual picture start. The cue marks on the ending reel should be on 3 frames at 192 frames from last image frame, and again 8 frames (I think) from it.
I have not looked at actual film in a lot of years. New prints would come with black dots for cue marks, usually needing a Clint Phare cue marker to scrape a tittle circle out of the emulsion to make them more visible. Or a huge X scratched through the image... the "drive-in" cue
So you need to figure what number on your leader gets the projector run up from stop to the end of the leader in 8 seconds. This is a bit of trial and error. Then whatever leader frame you started on to get that is your threading frame.
Test it and adjust as needed. Your reaction time has to be considered.
Some projectors start a lot quicker than others. With Simplex and Century - with a big flywheel on the motor - generally you thread around 9 on an old leader, don't recall with SMPTE leaders.
So you watch the ending reel, start the second machine on the first "motor" cue, then do the picture and sound changeover on the second "c/o" cue.
Movies were cut so that an error on changeover probably didn't matter much, no vital image or dialog right at the changeover. That was not true for a few movies in the 70s when platters took over and changeover houses faded away. A bad changeover could drop important dialog or mess up a crossfade.
Old prints that have been plattered by idiots often lose quite a few frames at the tail. The last frame would be cut off to identify the removed leader to its reel but idiots would keep cutting more off.
It was a lot of years ago but my first changeovers were very tense.

[Ed Gordon]

Also see: https://ausfilm.org.au/wp-content/up...hangeovers.pdf

The following text is taken from an old 35 mm manual.

[Ryan Gallagher]

I find this book from the George Eastman House to be an excellent beginner primer on all things film projection. Whole chapter dedicated to leaders, cue marks, and change overs etc.

https://www.amazon.com/Art-Film-Projection-Beginners-Guide/

i will add that if the cue marks are lab, there should be very little reason to add/improve your own unless footage is missing or a particularly bad frame/placement makes it extremely hard to see.

These days, in the back catalogs you may find all kinds of additional marks that warrant removing from prior operators.. Avoid scribe pens and stick to wax pencils. The general rule of thumb depending on your archive print source is no modifications if possible, except where damage is likely to cause further damage if run.