Zenza Bronica GS-1: Film Back Mechanics

Описание: In this video I show the mechanics of a GS-1 film back I opened for repair. The first part shows the components, while in the second part I used some test film to demonstrate the mechanics when the back is loaded with film. In the second part (from 03:52 on) I first forgot to engage the shutter (the pin in the mid of the back), which is why i keep rolling the gear wheel quite some time before realizing my mistake.

I really like how they engineered the back. Note that the frame counter advance is engaged by the roll over which the the film is pulled, not the mechanics for film advancement. This is crucial for keeping the gaps between the frames, e. g. if the paper on the film is slippery. Nevertheless, the frame counter advance is only engaged when the door is closed, which is why I keep pressing the tweezers against the side of the back. So the logic is: gear wheel advances film which engages the counting mechanism. If you test a back yourself, I strongly advise protecting the finger(s) you use to put pressure on the "door mechanics". The tip of my index finger still feels a little numb after some days.

If you have any questions feel free to ask.