Wednesday, August 26, 2009

Review of HiViz kits and initial results

I've always been intrigued with capturing images of things that we don't typically see. One way this is manifested is with freeze shots like splashes, water drops and light bulbs burning out. In the past I've done this using continuous drive mode, strobes and semi-random chance. Wanting to have additional control, last year I purchased a sound trigger, light gate and delay timer kits from hiviz.com. These types of projects being the somewhat low priority that they are, I finally finished them a couple weeks ago.

Since I have built many electronics kits in the past, I wasn't intimidated by the projects at all, but I wouldn't suggest them if you've never built a kit before. The kit is basically all the components you'll need with some hookup wire and a couple sheets of paper with schematics and directions. For an initial, temporary build, you can buy breadboards from HiViz and they have detailed pictures on their web site of the kits built on the breadboards. This allows someone not familiar with schematic reading to assemble them, but they're not a very permanent solution. In addition to the kits, I purchased a couple perf boards from Radio Shack and some cases and other miscellaneous items from Ra-Elco to finish the kits off.

In the end, this is what the completed kits look like:

(Click images to see larger view.)

I won't bore you with the specific build details, since there's nothing too exciting about the construction of the projects. But I will say, the timer was the most complicated with the highest parts count and the sound trigger was the simplest with the lowest parts count. Here's what the inside of the light gate looks like:

(Click images to see larger view.)

Probably the most interesting thing is I used 1/8" jacks for all three outputs and the delay unit's input. The Cactus wireless system I have to fire my strobes has one of these in the transmitter. This allows me to use standard audio patch cables to connect the output of the triggers either directly to the wireless transmitter or to the input of the delay unit which in turn can be connected to the transmitter. The sensors for the light gate and sound pick-up each have different types of connectors so it's impossible to mix them up or connect them incorrectly.

Another feature that's not standard with the kits is multiple resolutions on the timer. The delay kit comes with several different values of capacitors that control the maximum time for the delay. The idea presented in the kit is you decide which one you want to use and build your kit with only one of the capacitors. I decided to put a three way switch in so I can switch between them easily. With the values I used, I can switch between a maximum time of 10 milliseconds, 100 milliseconds or 1 second (1000 ms). I don't expect to probably ever need a 1 second delay, but it's there if I do find I need it.

In initial testing, they seem to work pretty well. All three worked correctly the first time I turned them on. The only real problem I've had is the sensitivity and timer delay adjustments don't seem to be active until about 1/3 of the way through the sweep of the potentiometer. After that they seem to work as expected. The panel mount ones I used are rated the same as what came with the kit so I'm not sure exactly where the problem lies. I have a couple ideas, but they work well enough I'll probably never dig into the reason; I'm more interested in using them than tracking down this anomaly.

My first test shots were with the sound trigger and delay timer. I setup my lights and camera in my "studio" (aka workshop, basement, storage) and plugged everything together. I set my camera to manual mode and took several test shots to dial in an acceptable exposure and then put it in bulb mode and put my remote release on it. Then I loaded my Airsoft gun, turned off the overhead lights, tripped the shutter and shot some balloons. In total, ten balloons gave up their short lives as I got the trigger sensitivity and delay dialed in. In the end, the last three all gave me very similar results. This proves to me I'll be able to get the consistency in these shots that I've been looking for.

Here are a couple of the better test shots. I'm looking forward to being able to spend some time getting some better shots setup and playing with these a lot more.

(Click images to see larger view.)
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