SUPER-8: -12, THE DAMNED FRAME.

2017 art design prototype

There is, when shooting in 8mm type S loaded in Super-8mm cartridges,  a damn frame: -12, that is, the one 12 frames before the exposure window, right where the convoluted coaxial design forces the film to wrap, around itself to go from one axis to the other.

If the Super-8 cartridge is left in the camera with the filming interrupted for a while, the film base get some deformation on that axis (a problem that is accentuated as more hours go by or under certain conditions of temperature and humidity): like the Super 8mm lacks a pressure pad in camera, this frame -12 will almost always be out of focus and will even produce some instability in the images immediately before or after (movements that, although they can be stabilized in post-production, are, however, visible if we enjoy the reversañ film with a projector). 

In the upper cartridge, Super-8, you can see the double loop that the film must stick 12 frames before the window. In Single-8 (the lower cartridge) the path is more direct and, in addition, cameras has a proper pressure pad

This problem in frame -12 is increased the thicker the triacetate base (as in the case of Provia film).

Not many people know that when Super-8 was designed, its film base was planned to be made of polyester, much more flexible and therefore immune to this problem. The problem is that when, at the time of going into production, Super-8 passed from engineers to accountants, and due to the higher cost of polyester, Kodak continued to make it in the cheaper cellulose triacetate.

Only Fujifilm, in 1965, presented its emulsions in polyester, and, moreover, in a better designed cartridge, with a more direct path in parallel axes (which allows integral rewind) and with space for the camera to have a metal film pressure pad (as also occurs in Double Super-8). Years later, also 3M manufactured in Italy Super 8 mm with polyester base. 

To avoid these problems, I personally reload Super-8 film onto Single-8 cartridges: this is a private activity, for my personal use!!! I do not do it for third parties: