Thanks for the interesting background Scott! Very useful (and a bit confusing).

Scott Stark
scottstark.com
Experimental Response Cinema
Flicker


-----Original Message-----
From: FrameWorks [mailto:[email protected]] On Behalf Of 
Scott Dorsey
Sent: Saturday, August 27, 2016 3:07 PM
To: [email protected]
Subject: Re: [Frameworks] oxberry 35mm repair?

Okay.... still 35mm films have "Kodak Standard" perfs, which are sort of 
squarish.  They are also used for print films, because they are stronger and 
don't tear as easily in the projector.

Motion picture _camera_ films have "Bell and Howell" perfs, which are rounded 
in such a way that an easily-manufactured registration pin fits into them.  
This allows cameras to be built with very tight registration that would be more 
difficult to do with KS perfs.

This is in ADDITION to the distance between the perfs being different between 
the print and camera films, to allow easy contact printing between the two.

But wait... it gets even wackier because there is a third perforation 
"Dubray-Howell" that is sometimes used for intermediate films.  And, Soviet 
motion picture cameras often used KS perf film (and their registration pins 
have to be modified to use them with Western film today).  But for the most 
part all you need to worry about is ordering KS for normal prints and BH for 
normal camera stocks.

It's not like 16mm where all you have to worry about is the pitch and the wind, 
due to a lot of historical baggage.

I was assuming that by "sprocket failure" you meant that the sprockets 
themselves were failing, not that the film was tearing at the sprockets.
If you have problems with the film movement, one thing to do is to get some 
junk leader and run it through the camera with the cover open and see what is 
going on.  However... if the camera has not been lubed in the last five years 
I'd worry about running it at all and I'd worry about tearing the pulldown 
mechanism up if it happens to be dry.  So I'd send it to Photosonics or really 
any good camera tech to take a look at it.
--scott

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