21 December 2015

High Speed Photography – Bullfrog

Jumping Bullfrog, Brighton, MI CC I used an infrared trigger and four high speed flashes to create this image.
Jumping Bullfrog, Brighton, MI CC
I used an infrared trigger and four high speed flashes to create this image.

I have had this image in my head for quite some time. The first step was to build the stage for our star “Billy Bullfrog”. A trip to the local swamp with a couple five gallon pails was required to collect all of the materials for the set. A lovely moss covered rock would be Billy’s launching pad. When I pre-visualized this image I thought I wanted a nice green background for the shot (see initial setup shot). But, after a few test images I quickly realized that Billy would pop of the background much more if it was black so I switched out the background for a piece of black velvet.

With the set built, it was now time to move onto the technical stuff. Once I switched out the background, I probably could have done this with just two flashes, but kept the four because it made it easier to even out the light. My flashes were Nikon SB-600s I had them dialed back to 1/16th power for a 1/11,000th of a second burst of light to freeze the action.
For my trigger I went with the Cognisys Range IR infrared trigger. The beauty of this system is the transmitter and receiver are in one unit. It sends out an infrared beam and if the beam bounces back to the sensor (off a frog for instance) it trips the shutter. Very simple to set up and only one piece of equipment to hide from the camera!

Jumping bullfrog setup click to expand.
Jumping bullfrog setup click to expand.

At this point I could have plugged the trigger into my camera and began making pictures. But Cognisys has a high-speed electromagnetic shutter that mounts onto the front of your lens. I wanted to try it out. The beauty of this shutter is there is virtually no shutter lag, it fires in less than 6ms! Most cameras have a shutter lag of about 100ms not a big deal for most types of photography. But as you can imagine a leaping frog can cover some ground in 100ms. Of course I could have framed the shot ahead a bit, to account for this, but I liked being able to know EXACTLY where the frog would trip the shutter. With the shutter on the front of my lens I plug the flashes and the Cognisys Range IR trigger into the shutter so now when the beam is broken it opens the high-speed shutter and fires the flashes. Next I open my camera’s shutter using the bulb setting. Now when the high-speed shutter opens it allows the light in to make the exposure. Once I get a trip I close the camera shutter and reset for the next image.

Okay, bring on our star Billy Bullfrog! A couple things I learned here… frogs can be quite stubborn and do not take direction well. They also do not necessarily jump in the direction they are pointed, and they can hold their breath for a very long time! But as usual persistence and patience won out in the end.

A special note of thanks to my son CJ who was a most excellent frog wrangler! I am pretty sure he is going to have warts after this? Oh wait that’s Toads. Heeey… Jumping Toad?

CEEE JAAAY! I have an idea…

Good Luck and Good Light!