I tried your trick of an LED in line with the hotshoe mount and a battery, and the Sony doesn't fire the LED. If the LED/battery/hotshoe-signals-to-ground loop is current protected, I can understand why. I've got to have a FET to respond to the trigger signal (current thru the hotshoe shorted triggering signal is very small, which is just enough to activate FET making drain->source go to short, then higher current flows thru that and LED). As for my circuit, I actully stole it from someone else here in another thread, there seem to be about 3-4 in various places about this subject:http://wetpixel.com/...t...st&p=278235
Got a few more shots up. Circuit now integrated into hotshoe and fits into housing. Didn't even have to put PVC or electrical tape over the 'rivets' on the inner face that hold the Ikelite top clamp on as nothing hits it that would risk a short. Just linking to the pics in a set on Flickr instead of embedding them all in this post, if you don't mind peeking. Never mind the scary bald man in the background of the triggering test.http://www.flickr.co...6388071/detail/
Had to drop to 2016 vs. 2032 batteries to use a shorter holder. That might be a problem in the long run as 2016's don't have the same current capacity. Still, the circuit works although the LED isn't as bright, and I was able to re-confirm it fires in the frame and will trigger a z240 held up to the outer wall of the housing (no fiber yet). It won't trigger the z240 if I hold it about 2-3 inches away, but the LED I have has only a 20degree lens arc and I don't know what the photodetector's arc is, so its hard to line it up perfectly by hand. More than likely if it triggers thru the wall with no light waveguide (fiber), there's enough light to trigger with a waveguide assuming I can get one rigged with the right orientation. I do have some flexibility still for moving around the LED in the trigger circuit, and/or adding a reflector behind it to help gather the light further.
I'm using a white LED, but the IR LED is interesting...wonder if it would work with the z240 photodetectors as well. Might give it a try. But if I have problems it'll probably be that I just don't have the gain I needed with the 2016 batteries and need to re-think an integration that lets me go back to the 2032's.
So the next step is coming up with a good fiberoptic link. I've got a small sample of (of all things) a near black Corian (the counterstop stuff...basically solid acrylic) which I thought I'd mill to get it to fit over the top ball mount on the housing and still let the ball fixture mount on top of it. The LED is placed sort of between the housing clamp handle and the top mount, so using that is perfect to hold the housing end of a FO link. Of course I'm too cheap to just buy a prebuilt FO cable, even though someone linked (on another thread?) a nice cheap Epoque one that has a stick-on housing end. Although I may find I regret it, I was going to drill the 'cap' for the photodetector that came with the z240 to mount some 3mm endglow fiber with a little ring of heat shrink tubing on the inside to captivate it, then use the piece of Corian to capture the 'input' end. Not sure if "ll need lenses or reflectors of some sort to help with the light coupling into the fiber....guess that's the next magic trick to figure out.
Edited by rtrski, 15 October 2011 - 04:22 PM.
Current rig: Sony SLT-alpha55 in Ikelite housing, Sigma 105mm f2.8 DC Macro w/ Ike 5505.58 flat port or Sigma 8-16mm f/4.5-5.6 DC HSM behind UWCamStuff custom 5" mini-dome. Dual INON z240 Type IVs triggered with DS51 for TTL mimicry, or DS51 alone with home-made ringflash assy for macro.
Topside, unhoused: Sony SLT-alpha99, Sigma 150-500mm + 1.4TC, Sigma 15mm diagonal fish, Sony 24-70mm f2.8 CZ, Tamron 180mm f2.8 Macro...all the gear and nary a clue...