Counters are an important control tool on an optical printer because you might want to flash a tiny spark into frame 39 or run a double exposure for frames 1138 – 2025 only. Or just keep track of how much footage you have printed.
After quite a bit of trial and error (as always) I’ve landed on a certain type of digital counter that has various features. It needs to count up and down obvs, but also needs to hold the number in memory so you always know where you are with long sections of film. With its additional relay its possible to get functions to stop at set numbers, useful perhaps for the future. One issue with these models is that the trigger control inputs are 0vdc, or ‘dry’ meaning they cant accept signal pulses form an Arduino (until I learn how to to do this). They can only accept ‘close-over’ connections that you find on micro and reed switches. The OX2 camera I’ve built uses an Arduino to control the motor so I can get around the 0vdc issue by triggering a 5vdc Relay that does the closing over.
To save me cutting a badly done slot into the lid I’ve gone for the clear lid enclosure style which I have to say I am very happy with even though it ended up being more difficult.
The switch above the counter will have a label saying FORWARDS to the right of the switch and REVERSE on the left. If I knew more about electronic systems I might not do it this way but basically the counter ‘doesn’t know’ which direction the projector or camera is running in even though there maybe somekind of circuit that does. So, you MUST tell the counter which direction you are going. This isnt a problem however because you already have at least half a dozen switches to keep track of when printing, why not add a few more.
Theres also the reset button still to do. This zeros the counter when you have laced up a reference frame. Perhaps drilling a few holes in the enclosure case is a good idea as the transformers do get a little warm.
The old CAMERA counter which works but has no memory can be used for someting else. I am going to use the clear lid style for all the counters now.
CEBEK
