Portable Wireless LED Ring FLASH

Hi All,

New to the forum, at least in its current incarnation, so I figured I would re-introduce myself with a show and tell. I built this battery powered hand hold-able ring flash - and I do mean flash as opposed to light, it only operates as a strobe. Power output is adjustable, but right now it does f/4.0 @1 meter, 100 ISO, 1/160sec. Actual duration is 2 milliseconds, requiring a shutter speed of 1/160 (60D) to capture the whole thing.

Taken with above.

Hey that's cool! It looks good, I have a few questions. What emitters did you use? How did you mount them?

Used 10 watt white from ebay. Had to grind them down to fit that many in the housing. Driven at twice rated power, but briefly enough that it doesn't matter. Testing at even higher power has proven them to be quite rugged! Mounted with double sided foam tape.

This is a previous prototype. You can see I had a tough time shoe-horning the electronics into the existing enclosure.

Awesome rig.

I was wondering if you had tried over-driving the emitters! At very high speeds (<5 microseconds) you can seriously abuse them without causing damage. I've never tried it at millisecond speeds.

I assumed you used a basic microcontroller + transistor to control it, but your prototype is a bit more complex... Any more details on the controller?

It looks like you have alternating LED colours, or is it just me? Is that to control the colour output?

The LED's are alternated "cool" and "neutral" because I found one to be too purple and the other too yellow... now it's about 4500K and it helps to remove some green. Skin tones need a bit of fiddling in post. The controller is in essence what would happen if you took a standard dumb flash circuit and substituted a long series string of LED's for the tube.

Thanks for the info. Gotta say it looks very good!

I was debating whether or not to start a new thread, but I built another large dia ring flash, this time with actual flash tubes. 16 of them, sourced from disposable cameras. Identical housing, so looks outwardly just like the LED flash above. From the amount of capacitance (energy storage) I'm using, I expected more power, but the housing is very unfocused and has such a large spread, it's only about as powerful as the LED one, about f/4 at portrait distances. At least I have good color and can shoot at 1/250s. Added some White LED's as focus lights, so it is completely portable, wirelessly triggered, and usable outdoors at night, which was my design goal.

It's light enough to hand hold in whatever position I like, while operating the camera with my other hand.
In this example, I didn't actually shoot through it but held it about 6 inches above the lens.

Man, I miss Halloween!

Nice, how many shots did you get using the LED version compared to the flash bulb version from the two AA eneloops?
Did you try hooking it up to your flash hotshoe to trigger it (maybe with a wireless adapter)? Or triggering the shutter at the same time as the flash using the remote shutter port on the camera?

I have yet to run either flash long enough to drain batteries, but I can tell you the LED's are much more efficient. Minus the power supply losses, they consume about 2.5 joules per pop, where tubes consume about 12j.

I'm triggering with a dumb Yongnuo hotshoe trigger, with the receiver built into the flash enclosure, and powered by my circuit so I only need one set of (4) batteries.

This is what it looks like with diffuser in place

Awesome, I bookmarked this as inspiration for when I have time for some fun projects to work on. I'm guessing you bought a cheap crappy ring flash to use as the housing?