What signal is required to trigger a camera flash?

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What signal is required to trigger a camera flash?

Postby FPS » Sat Feb 22, 2014 9:11 am

I'm curious as to what signal does the camera axe send to the flash to trigger it? I want to make a simple manual trigger. Do I need to power it or is it just a simple switch?

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Re: What signal is required to trigger a camera flash?

Postby erniehatt » Sat Feb 22, 2014 8:30 pm

it's an optocoupler chip that triggers the camera of flash
If the world is a roundabout, no wonder I am always in a spin. Cheers Ernie

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Re: What signal is required to trigger a camera flash?

Postby FPS » Sat Feb 22, 2014 11:46 pm

Ok. but the optocoupler is just the switch correct? what is the simplest way to trigger a flash? is it just a drop in resistance?

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Re: What signal is required to trigger a camera flash?

Postby FPS » Sun Feb 23, 2014 1:15 am

I found the answer, I had a broken sound sensor for the CA, plugged it into the flash, stripped the wire and the flash was triggered by connecting the red and yellow wires. So its just a simple switch, now I just need to know what resistance drop is necessary to fire it.

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Re: What signal is required to trigger a camera flash?

Postby Maurice » Mon Feb 24, 2014 9:34 am

I don't understand the question... The sensors use logic values and has various modes ranging from digital to analog working on 0-5V. The optoisolator just acts as a switch and devices you plug in there (cameras or flashes) are current limited and thus need no resistor.

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Re: What signal is required to trigger a camera flash?

Postby dscpcb » Tue Sep 29, 2015 6:33 am

Flash triggers are devices that relay a signal from your digital SLR camera to the flash unit, telling it to fire.

I believe by far the most common trigger in use is the camera's hot shoe itself.

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