Triggering a camera with light

Hello, was wondering if I could pick people's brains for how best to approach a project I would like to do.

Basically, I have a camera trigger set up for taking photos of 3D print time-lapses using a physical switch that the printer will make contact with and take a photo on each layer resulting in this:

But I would like to adapt this to work with a resin printer and have it trigger when an LDR detects the light exposing each layer. And wonder how to go about this with minimal components.

The "light" is probably UV of some specific wave length. You need a sensor that will reliably detect that wavelength.

Yep, its ~405nm so in the visible spectrum and detectable by jellybean LDRs (well enough for this application I would assume).

Unless you are good with an LDR response time I would consider using a photo diode or photo transistor with sensitivity in the range you have.


Have a 2.7 second window there the printer is stationery while the light is being projected. I hope that is enough for the response for the LDR, and camera to trigger (will be using manual focus to reduce the trigger time on the camera side of things.

Right now I just have the circuit for the trigger side of thing, implementing the "switch" side of it, not sure of the best approach.