A Compact Flash for Canon A-1 Film Camera

from hackster.io

Joshua Bird recently purchased a Canon A-1 film camera, manufactured in the 1970s. While lacking some capabilities compared to dedicated digital cameras — not to mention smartphones — it’s an interesting piece of functional tech history.

After a few initial issues, he finally got a film camera that worked as intended, but found that this setup requires a significant amount of light to operate properly without a tripod.

An alternative would be to use a flash, however, options found online tend to be quite large. Naturally, Bird “didn’t exactly want to show up to parties looking like the paparazzi,” and decided to make his own compact flash unit, using the flash circuit from a disposable camera that cost around $7 US. The challenge here is that the unit is charged up to 300V before producing its quick burst of illumination.

This voltage level means that, first of all, the device's capacitor needs to be discharged before handling to avoid personal risk. Cameras can’t generally switch 300V without frying the electronics, so he designed a circuit that allows the camera to trigger it with just 5V from the hot shoe, based on the circuit found here.

This setup triggers the flash at the same time as the shutter, for well illuminated images without significant bulk. The new flash has a charging toggle switch to keep the battery from discharging, as well as a 3D-printed housing to keep everything in place and protected. Build files are available on GitHub.