8mm Forum: Leader thickness

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Posted by Barbara Strohl (Member # 5227) on March 23, 2016, 12:25 PM:

Are all leaders the same thickness?

I thought that s8 leaders were just slightly thicker than the film itself. Is this true?
Are 8mm leaders also thicker than the film?

I'm sorry for the noob question but I am looking to make a rig that is dependant on uniform thickness.

Thanks.

Posted by Steve Klare (Member # 12) on March 23, 2016, 12:55 PM:

Hi Barbara,

Welcome!

This is one of those things that's hard to generalize.

For one thing not all film is the same thickness. You have acetate and polyester bases for example with acetate thicker than poly. You also have acetate and poly leaders which should also be different thicknesses. As you mix and match these materials you can get all sorts of combinations of thickness.

What you run into is film gear was designed to be very tolerant of film thickness, so it is the one dimension of all of them that isn't as critical. The only time you run into trouble is splicing stock of different thicknesses and experiencing a slight loss in focus when you project the film.

Most of my splicing is beveled acetate splicing and the two beveled edges match between leader and film, so I feel semi-safe saying Kodak acetate film and leader are the same thickness...in my experience...as far as I know!

Then of course you throw in the thickness of the splice itself: beveled cement spice: should be flat, tape splice: a little thicker, overlapped cement?: like hitting a speedbump doing 60!

We are gear people as much as film people here. What does your rig do?

Posted by Barbara Strohl (Member # 5227) on March 23, 2016, 02:49 PM:

I was afraid of an answer like that.

I am looking to digitize family movies that are 8mm and s8. Some of them look like they have never been played and leave me with a number of options. Some are in much worse shape.
There is one that I really want to recover that is brittle, broken, and accordioned in places.

I am looking at using my flatbed scanner to digitize the film. I have trays that fit it for many different positive and negative films but not movie film.
I have looked online at what others have done and I have come up with a vision of what I want to setup.

One reel > dusting (brushes, PEC, or air) > channel tray that will hold the film straight and flat and be capable of taking wet film > uptake reel

The tray is what I am looking to create.
I am debating polished beveled edge glass vs a thin optical plastic that is easier to cut.

I had been thinking of channel guides that either side would slide through but for this to work best I need a set thickness.
I could use two plates that would "press" the film but that is difficult to automate. Maybe save that idea for the worst and just babysit it.
Wetting the film and leaving the fluid do the work is ok for quick bits but too much liquid becomes messy and too little causes artifacts.

From what I've seen, I only need edge guides for film in good shape. That is easy. It's the ones in bad shape that I am thinking about.

I'm sorry for the rambling.

Posted by Steve Klare (Member # 12) on March 23, 2016, 04:14 PM:

Wow!

That sounds like quite a project!

There is good news here. If it's only home movies, odds are very good we are only talking acetate based film.

Poly is the domain of commercial prints and home movies made using the Fuji single 8 system, which is at least unusual in North America.

So you should be talking 100% acetate film. The variables after that are the leaders and the splices.

Posted by Barbara Strohl (Member # 5227) on March 23, 2016, 06:36 PM:

Thanks.

I am finding a steep learning curve going from stills to movies.

Posted by Steve Klare (Member # 12) on March 23, 2016, 06:45 PM:

It is different.

Years ago when there was still such a thing as a Fotomat, I handed over my movie film to the nice young woman inside the booth. She asked "What finish do you want?". I said "No, this is movie film.". She said "Ohhhhhhh!!!...What borders do you want?".

I said "Sprocket holes, please!"

I think if you find yourself some Kodak acetate leader and tape splice it, you can establish a pretty uniform thickness. Tape splices are actually very thin and shouldn't make a huge difference.

Posted by Will Trenfield (Member # 5321) on March 29, 2016, 06:50 PM:

I think that there can be a variation in thickness with leader film. I found that my Eumig S 710 was chewing up the cheap leader on one film. When I spliced Kodak leader on instead, it ran perfectly.

Posted by Osi Osgood (Member # 424) on March 30, 2016, 11:45 AM:

I might be wrong, but I think that the thickest of the leader was that TOTALLY AWESOME green "protect a print" leader, which was supposed to "clean" you're projector as the leader went through and it actually did a decent job of it. Very RARE stuff these days!

Posted by Joe Balitzki (Member # 438) on March 30, 2016, 11:55 AM:

Protect-A-Print Leader is probably the thickest leader but its also somewhat abrasive so I do not recommend it

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