Saturday, July 2, 2011

High-Speed Flash with HiViz

I've been playing with high-speed flash photography for a number of years now -- capturing short-duration events using a VERY short flash exposure. I even built my own sound trigger circuit a few years ago, which worked but was a bit flaky. Recently I decided to upgrade to a more stable and repeatable setup, which led me to HiViz and their lineup of products developed especially for high-speed flash photography.

Loren Winters, who runs HiViz, has spent years providing kits for DIY-inclined photographers wanting to get into the fascinating world of high-speed flash photography. Over the years his offerings have gone from simple circuit diagrams to breadboard kits, and now to fully-assembled and tested PC-board based multi-use circuits...all at fire sale prices. It's clear Loren makes his products available for love, and not to become a millionaire!

I purchased Loren's Multi-Trigger PC Board Kit, a well-designed multi-purpose triggering setup that lets you trigger a flash by sound or optical interrupters, with or without a variable delay, for $29.95. It includes everything you need to build and use the circuit, including a piezoelectric transducer (microphone), two different optical interrupters, all of the electronic components, switches, wires, etc. and a sturdy PC board to build the kit on. If you don't have experience building circuits (or don't want to bother doing it yourself!), you can buy a fully assembled and tested version of the circuit from Loren for $75.50. The kit price is a real bargain -- pricing out all the individual components myself, it would cost me $25 at least just to get the parts *without* a PC board.

If you've ever done electronic circuit assembly/soldering before, you should have no trouble building the kit version yourself. It took me a total of about 8 hours of very slow and careful soldering, triple-checking everything as I went, to get the circuit assembled. The instructions on the HiViz web site are clear and easy to follow. Just take your time, and be careful with the small parts!

The concept behind a high-speed flash trigger circuit is pretty simple: you use some external "event" to trigger a speedlight set on a fairly low-power setting, and that very short duration flash pulse from the speedlight (typically around 1/20,000th to 1/30,000th of a second) is short enough to 'stop' fast-moving or hard to capture moments, such as a light bulb breaking or the splash of a water droplet. The usual shot setup involves working in set everything up, turn off the lights, lock your camera's shutter open on "bulb," then let the event trigger the flash, recording an exposure. Close the camera's shutter and you're done.

The sound trigger of the HiViz Multi-Trigger lets you get shots like the one I did above -- the microphone was set up just outside the frame, and when I dropped the bulb and it "popped," the sound triggered my Sigma EF-500 DG Super flash at 1/16th power to flash once, capturing the bulb breaking. The water drop photo at the top of this post used the optical gate trigger of the HiViz -- as the water drop passed through the photogate, it set off the delay circuit, which about .09 seconds later triggered the flash to catch the rebound of the water drop.
You might be familiar with lots of water-drop high-speed flash shots on the internet, and with a fair number of "shooting things will bullets" shots as well. I have some other things in mind for my new robust, reliable trigger circuit, but these first tests were to verify it worked. It does, and it works very well indeed. I can't wait to start shooting some of the ideas I have in mind, and I'll post the results up here as they come in. Big thanks to Loren Winters at HiViz for such a well-designed and affordable entry into this fascinating aspect of photography!

Some other high-speed flash sites to look at and whet your appetite:
Martin Waugh's Liquid Scuplture
Photos by Kev

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