Bright IR light that can trigger camera flashes/strobes?

Hardware Hub
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I’m building a photo booth app for iOS and Android using Flutter.

One problem that many mobile photo booth softwares have is that they only support static lighting, meaning they have no way to trigger a strobe or speedlight. Static lights (lights that are always on and don’t “flash” like a camera flash) have a few drawbacks compared to strobes and flashes (not as bright, can’t be used to freeze motion, draw a lot of power, etc.)

I really want to find a way to trigger studio strobes and light using the “optical slave” feature that many lights have. Many flashes and strobes have a feature that will trigger the flash when they detect a strong enough light impulse. The light doesn’t have to be visible light. I don’t know what part of the spectrum or the intensity of the light that would be required, nor do any of the flash manufacturers make this public, so this will be a bit of a trial and error experiment. I suppose I could do some experimenting with a light meter to figure out what’s required to trigger the speedlight/strobe.

My idea is to have the app use blutooth to signal something like an RPi, which will then trigger the IR light, which will trigger the flashes.

Why not just use a cable to trigger the lights? Well, often times it’s not practical to have cables ran from the device to the light(s).

Another option I considered is to just use the Pi to trigger a flash that’s mounted in the housing with the tablet, but I’d rather do it with a standalone IR light if possible.

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I doubt bluetooth would reliably trigger at the right time…

You’ll probably need to sync the flashes directly to the output of the LED “flash” on the tablet. Something like below with the optical sensor sandwiched up against the tablet’s flash.

Once you have a single flash unit triggering by wire any number of additional flashes can be triggered by the flash from the primary flash.

Also, make sure you can even use the flash with the camera on the tablet at all via something as high level as flutter…

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I think the latest OnePlus phone (OP 12, IIRC) has an integrated IR blaster.

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Have you thought about using an IR signal timed through the headphone jack? It’s possible to do even through a DAC. I’ve also seen USB C IR transmitters for smartphones.

I don’t know the specifics on how to integrate it all in your app, but it’s worth looking into it in my opinion.

If you want to use an external trigger I’d use an NRF24 to trigger the flash or a 433MHz signal, not bluetooth because it’s way too laggy. But, as before, I don’t know how you’d go about hard wiring a transmitter to an Android phone to trigger a flash.

I’m brainstorming and hopefully coming up with something that makes sense!

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