I recently ran a workshop at the national convention of the Photographic Society of New Zealand. The object was to introduce particpants to a different way of taking photographs: open the shutter and let a flashgun (= speedlight) freeze the action. It was great fun, rather messy and I think did inspire one or two to go away and try some stuff on their own.
(we did not actually get into water drop photography – this shot was included just to get your attention.)
I’ve listed the links which I have found extremely useful, at the end of this post. You can download my workshop notes here (2MB, sorry if they’re a bit cryptic).
The flash units required for this work can be picked up very cheaply these days. There’s usually one or two suitable units amongst the very cheapest offerings on Trademe, for example.
A suitable flash must have:
But it does not need to:
The basic idea is well known. Set your camera to manual focus, an aperture of somewhere between f/8 and f/16 and a shutter speed of about 1 s. Focus on the spot where the action will take place, darken the room, press the shutter and (some time during the 1 second exposure) fire the flash. Our room was kept permanently dark and focusing was done with the help of a small torch. We used various triggers to fire the flash.
Flash triggers
The first was extremely simple, a contact trigger which I had made up from a few sheets of paper, photo matt board and aluminium foil. The moment something touched it, the flash went off. We dropped dice, small balls, M&Ms.
The second was a simple sound trigger: a piezoelectric disk with a simple circuit providing sensitivity adjustment. We could generate various delays by moving the piezo microphone closer or further away. Here the subject matter was balloons. Occasionally empty, usually filled with some cornflour and eventually, in response to demand, water.
The final activity utilised a light beam trigger. We dropped small rubber balls into a large vase full of water. The trigger unit had a delay circuit, so we could generate different effects.
(Postscript: In June 2014 I ran another workshop in Nelson. Here’s a great example of what we can get from the light beam sensor:
https://www.flickr.com/photos/foxview/14306017258/in/photostream/ )
Arduinos
My presentation covered some alternative approaches which we did not attempt on the day. Rather than be reactive and use a detector to determine when something has happened (and then fire a flash), microcomputers have become so affordable that it’s now possible to control everything. The flash can be fired at a precise moment.
Links:
Here are some useful links:
Flash trigger voltages (a must read before you connect an old flashgun to your expensive digital camera, not so important when they’re used off-line the way we use them):
http://www.botzilla.com/photo/strobeVolts.html
A very clear illustration of the effect of winding down the power setting (as well as a demonstration of why most studio flashes don;t work for this stuff):
http://www.scantips.com/speed.html
For all you ever want to know about Nikon speedlights, just Google “ Nikon speedlight site:mir.com.my “
The best site I’ve found on DIY triggers, plus kitsets and made-up units: http://hiviz.com/index.html
The contact trigger used in the workshop: http://hiviz.com/tools/triggers/triggers1.htm
and the sound trigger: http://hiviz.com/tools/triggers/triggers2.htm
Finally, the multi-trigger used for the light beam shots: http://hiviz.com/kits/mt2.htm
Other commercially available trigger units:
Camera Axe: http://www.cameraaxe.com/
Stop Shot: http://www.cognisys-inc.com/home_cogn.php (After a similar workshop last year at our Nelson club, one of the members went off and bought one of these. Within a week, he had results every bit as good as my best!)
Trigger Trap: http://triggertrap.com/
Water Drops
A great place to buy Arduinos (or their clones): http://dx.com/
The Arduino reference site : http://arduino.cc/
“Droplet”, Stefan Brenner’s great user interface for Arduinos and water drop photography
http://www.stefanbrenner.com/liquid-art/droplet/
Markus Reugels, another great pracitioner: http://www.markusreugels.de/
Tobias Bräuning, another expert on water drop collisions: http://www.t-braeuning.de
An e-book on water drop photography (covers not just the gear, but lighting and fluid chemistry as well) http://www.liquiddropart.com/