Film-Tech Forum ARCHIVE: splice finder

This is topic splice finder in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=004172

Posted by Russell Smith (Member # 1481) on 11-04-2002, 03:12 PM:

I'm building a splice finder for my final year project at uni.

The aim of this project is to help the projectionist save time when assembling and dismantling films, and to help keep the picture clean and stop the digital audio tracks getting damaged. This will improve the quality of the overall performance of the cinema.

I have built a cinema film frame counter, and I'm expanding it, so it remembers where splices are. it will give an audible/visual warning on approach, so you don’t have to mark to surface of the film. Possibly, as this warning system is logic driven, it could drive a motor to find the splice for you at the press of a button. I also plan to have automation change memory locations so we can lose the foil tabs.

The film is made up on a “rewind bench”. It is on a plate on the left, and goes across (not touching) the splice tool, to the take-up spool which is on the right. I plan to have the film counter positioned between the plate and the splice tool, so the projectionist can pass the film through it, and when he/she makes a splice, he/she can press enter on the counter to store it to memory.

I want to be able to scroll through the memory locations, so they can be edited if need be. Also, it needs to be able to switch between splice locations and automation change location. Then when the film is being broken down, the device will be switched to replay mode. A small replay counter will also be needed for the projector to do the automation change process.

If anyone thinks this is a good idea, is interested in the progress, or can give any advice or ideas, please don't hesitate to get in touch with me. Thanks for giving time to read this and I hope to hear from someone soon.
Russ

Posted by John Pytlak (Member # 331) on 11-04-2002, 03:26 PM:

"Frame Count Cueing" is often used to make scene-to-scene light changes during printing. It replaced film notching or application of foil cues to the printing negative.
here Frame Count Cueing
here DuArt FCC System

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: +1 585 477 5325 Cell: +1 585 781 4036 Fax: +1 585 722 7243
e-mail: john.pytlak@kodak.com
Web site: here

Posted by Dustin Mitchell (Member # 372) on 11-04-2002, 04:48 PM:

Your idea has a lot of potential in regards to print inspection. Quite honestly I've given up inspecting prints by hand due to lack of time. Any errors will be caught when we screen them the night before anyway. However, with your device I could set a reel spinning on the rewid bench and load a few films t the same time. The key, however, is to make it affordable. If it gets to be too expensive it won't have a life beyond archives and other places that inspect a lot of film.

As for its application in breakdown of movies, not needed. I have pretty poor eyesight, likely the worst of anyone posting on Film Tech that still works in a theatre. However, my fingers work just fine for finding my unmarked, clear tape splices.

Posted by Leo Enticknap (Member # 534) on 11-05-2002, 01:52 AM:

quote:
I have built a cinema film frame counter, and I'm expanding it, so it remembers where splices are.

Someone wrote an article in Cinema Technology describing a system like this about 4-5 years ago I think. I remember thinking at the time that it would work pretty well in the case of brand new release prints that are handled perfectly throughout their time in a given cinema, but that the problems would come with older prints, prints of rep titles and when accidental damage happened.

If I'm understanding you correctly, then for the system you propose to be 100% reliable, the only joins permissable throughout the length of a print are the ones at reel ends. Once you're dealing with more of them then the potential exists for it to get confused. For example, what happens if you have a platter wrap in the middle of a reel which mangles a couple of feet beyond hope? Firstly, you've introduced at least one extra splice and secondly you've reduced the length of the reel by two feet or so.

So I'd guess that you'll need to build in error checking devices. Firstly, the system will need to remember the length (in feet and frames) between each of the splices that you have made, and thus stored in its memory. Therefore if, when packing the print off, the system finds a splice in a position that does not correspond to the length it's expecting, it will know that it isn't a splice that was made when the print was originally prepared. And in the case of very old rep prints in which you can easily have 10-20 splices in each reel, it will need a facility to detect and remember how many 'false alarm' splices (i.e. ones which you didn't put there) there are between the actual reel end splices that you've made. Again, if you have to introduce a new one following a film break, it will know that it wasn't there when the print was made up, and should be capable of picking up the sequence of 'false alarm' splices through to the next reel end thereafter.

Finally, whatever method you are using to detect the splices (an infra-red beam?) will need to be able to distinguish between tape, cement and ultrasonic splices. The ability to detect defective splices (e.g. ones with several layers of tape, are at a skewed angle or with a massive overlap) and warn the projectionist to remake tham would also be very useful.

Posted by Russell Smith (Member # 1481) on 11-05-2002, 05:27 AM:

Thanks for the interest guys,

The system is nearly built, I only need to work on the program for the micro controller and the price should be as cheep as about £15 for all the electronics. I found an opto-coupler can detect the sprocket holes, then I divide by four to get the frame count. The micro I'm using also has flash ram, so it will hold its ram when switched off. I'm more worried about the cost of the rollers etc.

Surely if you feel for the splices when breaking down the film, you would be damaging the Sony SDDS soundtrack that other cinemas might want to use?

Also, well remembered about the article in Cinema Technology, it was written by Roger Lownsborough, the chairman of the BKSTS education and training committee in April 98. He’s my project supervisor at Southampton Institute.

The system won’t actually be detecting the splices, it will only be remembering what frame they are located at, so it won’t get confused when it comes across splices due to accidental damage.

Posted by Leo Enticknap (Member # 534) on 11-05-2002, 05:40 AM:

quote:
The system won’t actually be detecting the splices, it will only be remembering what frame they are located at, so it won’t get confused when it comes across splices due to accidental damage.

OK, but could it get confused by lost footage caused by accidental damage?

Posted by Brad Miller (Member # 2) on 11-05-2002, 05:32 PM:

quote:
"Surely if you feel for the splices when breaking down the film, you would be damaging the Sony SDDS soundtrack that other cinemas might want to use?"

That method does not damage the SDDS tracks.

Posted by Russell Smith (Member # 1481) on 11-06-2002, 05:18 PM:

"OK, but could it get confused by lost footage caused by accidental damage?"

I plan to have a warning beep aproximatly 10 frames either side of the splice, So if it's not dead on, it will still get you close to the splice.

"That method does not damage the SDDS tracks."

O.K. I'll take you word for it, but if that method is o.k., and it's fast enough, why do people mark the film at all?

Posted by Scott Norwood (Member # 30) on 11-06-2002, 06:06 PM:

The only reason to ever mark splices on platters is to distinguish between splices at reel breaks and repair splices. With new prints (which rarely have more than one lab splice per reel to remove), this isn't normally an issue, so there shouldn't be a need to mark anything. With old, splicy prints, though, it sometimes makes sense to use zebra tape or other marking methods.

As for damaging the SDDS tracks, I doubt it's an issue. How many prints have playable SDDS tracks after they leave first run houses, anyway?

Posted by Joe Beres (Member # 678) on 11-06-2002, 07:14 PM:

Could something akin to an RTI Evaluator splice detector be developed into a make-up table? Some of the RTI 16mm machines had a device that would sense splices and or perf damage and stop the machine. I haven't taken a close look at how it is done, but I would assume it could be doable and useful for make-up & breakdown from a platter.