DIY Optical Slave Trigger

I want to make up my own underwater optical slave trigger using a cheap topside optical slave trigger.

I have an old sync cord that i want to wire to the hotshoe of the slave trigger....pretty straight forward.

But i need some ideas on waterproofing/pressure proofing it.

I have two ideas so far:

1.\ Get an old point and shoot housing, and put the optical slave trigger inside it. Drill a hole in the housing for the sync cord to come out of. But what would be the best way to create a watertight seal where the cord enters the housing? Any ideas please?

2.\ Dip the slave trigger unit (with cord already wired to it) in some type of opaque resin that will pressure proof and waterproof the whole unit, yet allow light to still enter so the trigger is activated. Does anyone have any ideas on an appropriate substance that would acheive these ends?

I want to make up my own underwater optical slave trigger using a cheap topside optical slave trigger.

 

I have an old sync cord that i want to wire to the hotshoe of the slave trigger....pretty straight forward.

 

But i need some ideas on waterproofing/pressure proofing it.

Hi Pfuller,

Clear Cast brand resin will work to give you a seal for your optical sync and is easy to work.

You might consider something to make your sync directional or every time a wave flashes sunlight at your housing or a friend's flash fires, you could have your flash fire.

Good luck,

Barry

www.marinekeywords.com

www.creativeillusionsphoto.com

I've just recieved my optical trigger and have sourced an old sync cord to operate on.

Last night i was testing out how i was going to hook the sync cord wires to the optical trigger and ran into an issue.

The hotshoe is pretty basic; centre pin is the trigger, and the outside of the hotshoe is the ground. The optical sensor just uses a photoelectric effect to power the trigger signal, so no power from the strobe (or internal battery) is required.

So hooking the sync cord to the hotshoe via the trigger (white wire) and ground (black wire) was pretty straight forward using the following as reference.

http://www.ikelite.com/faq/faq_syncwiring.html

Now, when the optical trigger sees a flash, it triggers the ikelite strobe as desired. Brilliant! However to get the strobe to fire again (triggered by subsequent flashes), i have to disconnect the sync cord from the hotshoe and reconnect it. Its almost like its keeping the circuit open after its triggered, so i have to break the circuit somehow after the strobe has fired.

Does anyone have any ideas how i might be able to address this problem?

Electronic is not my area of expertise, but have you tried to invert the wiring, I see issue with Canon camera who have an inverted polarity and will need some gadget to invert the polarity to work with some studio flash, could be its a similar issue, mind you it would be a first for me as far as underwater strobes are concerned. I dunno, might be worth a try.

I've figured out what the problem is, but i have no idea how to fix it.

The optical trigger apparently drops the voltage of the trigger from 5V down to ground when a flash is sensed. For some reason, instead of the trigger returning to 5V, its staying down at ground, so subsequent flashes wont trigger the strobe.

I think i need a capacitor, or to somehow hook in the ready light to get the voltage back up. My electronic skills are limited though, so if anyone has any clues about this stuff let me know.