Roger: More Ideas

[dogstarman]

Roger,

I contacted you a while back about an idea I had for camera/ sound sync... I cn't find my notes, but I'll try to get with you on what I can remember.

Second thing: if you want to try to develop a new prodect for S8, I've got one for you:
a new RELIABLE reloadable cartidge.

OR

A magazine that works like the old 200' cartridges BUT holds DS8 film. The way I imagine it, most cameras that could accept 200' carts had the normal film door and a second door that flipped up to insert the 200' cartidge. So, it seems that you could adapt a 16mm magazine in the following way:

The first thing would be to adapt the magazine so that it ran at the same speed as a S8 camera. This would probably be easy for someone like you.

Second, you would have to fabricate/ adapt a unit that would fit onto the bottom of the 16mm magazine. This part would would fit into the cartridge area of the S8 camera. As I recall, most cameras that accepted a 200' cartridge were sound cameras. As such, you could make the unit large enough to occupy the entire chamber. The film wouldn't neccessarily pass throught the sound capstan and head, but it would depress the sound capstan switch, thus making the camera run at a more constant/ stable speed.

The part of the unit that fits inside the camera would (I'm thinking) just be a plastic/ metal shell that could be opened up to thread the film through. Inside, there would just be a couple of rollers to guide the film back up to the magazine. The claw mechanism would advace the film, and the take-up mechanism in the mag would do the rest of the work. The only problem that springs instantly to mind is the torque neccessary for the claw to pull the film out of the magazine, but I have no idea how to compensate for that...

Just an idea. Build one to work with Nizo sound cameras and I'll buy one... I'll get back to you on the reloadable 50' cartridge idea, I gotta' run.

Sam

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[dogstarman]

Ooops... forgot:

The pressure plate. Hmmmm.....

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[MovieStuff]

Well, years ago I did fabricate a 400 foot mag for a Fuji ZC1000. Now, THAT was a sweet set up.

The thought of making a reloadable 200 foot cartridge has crossed my mind. However, there are a couple of issues that need to be addressed.

1) Making the magazine is pretty straight forward. Getting 200 foot super 8mm daylight reels might be more of a problem. Without them, you would need to use core loads, which means fabrication of some special super 8mm cores.

2) Like the WorkPrinters, super 8mm cameras have no formal "loop" to isolate the tugging action of the take up reel from the gate. Therefore, pressure plate tension is super critical. You want enough pressure plate tension on the film that so that the take up can't advance unless the advance claw allows it to for each frame change.

In other words, the take up reel is always TRYING to pull on the film but can't because it is wedged in place by pressure plate tension. When the claw pulls down the next frame, the take up reel is allowed to take up only that one frame amount. This happens 24 times per second and can be quite violent! So tension is critical.

The amount of torque needed to pull film off the feed reel is doodly-squat, especially at the beginning of a reel where leverage is the greatest. Torque becomes a bigger issue at the end of the reel. Conversely, the take up reel has more power at the beginning of the run that at the end, since it loses leverage as it goes.

I wish I had an old 200 foot mag around. Alas, I no longer have one to play with, but I'll see what I can do.

Roger

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Roger Evans
MovieStuff
http://www.afterimagephoto.tv/moviestuff.html