We are a media production firm that has evolved over the years. Several years ago our core business was 35mm slide duplication. Recently, when a client asked if we could digitize several rolls of 16mm film, I said, “Yes.” I knew our digital camera attached to a bellows unit could be mounted on top of the old 35mm slide light source on a copy stand. I didn’t know how I was going to move the film under the camera. But I did know the process had to be automated to move the 150,000+ images through.

   It was obviously important to move each frame into exactly the same position relative to the camera lens as the previous one. This required accurate control over the absolute position of the film as it is moved under the camera. A stepper motor with fine step control was the obvious choice. The solution for this part of the project was to use a Stepper Pack from PC Control Ltd. It had the control board (stepper bee) and a 200 step per rev stepper motor with enough torque to move the film. A transport device was designed and built by myself and a friend. The film is sent through two film guides (taken off an old 35mm film trimmer) and then fed through two wheels mounted on top of each other.

    The lower wheel is rigged with a spring to provide tension against the top wheel. The film is pinched between the two wheels, wrapped with rubber bands.  The top wheel is mounted to the stepper motor. I used the software (Autostep) which was supplied with the stepper pack to control the movements of the stepper motor.  Once the correct number of steps between frames was worked out together with the duration of the hold time of the frame, the sequence was made into a continuous loop  The Fuji S5 camera, with AC power, is tethered to a computer via a USB cable.       
 

   Fuji has camera shooting software, allowing the camera to be controlled by the computer. We used the camera shooting software to trigger the digital camera. On reflection we could have omitted using this and simply used additional facilities on the stepper bee. It has some additional switching outputs (6) which can be linked to the step sequence. One of these could have been used to trigger the camera via the standard external sync connection.

   Pauses were added to to allow enough time for the image to save to the computer, while the film was advancing. A 16mm film projector was added as a take-up reel. Constant tension from the take-up motor allowed the film to advance a constant distance when the two tensioned wheels turned. The set-up worked great. So well, that once going, an operator was not needed to tend to the process..