In my day-to-day routine I often find myself having to do extensive photographic documentation of objects or locations, only there is often someone waiting to turn off the lights, or move objects, or any myriad of possible interruptions. This is one reason why using a camera tethered to a laptop can be a pain. The computer is a burden to travel with, takes five minutes to boot, the batteries run low, the ten minutes you had to get the job done just became five… It occurred to me that if I could somehow tether a DSLR to an instant-on device like an Arduino microcontroller I would have less weight to carry around and could get more work done. After mentally spec’ing out what I would need, I realized the solution was right in front of me – because I bring it with me for Mario Kart wireless races on long night jobs – (In the manner of John Lasseter’s slow epiphany voice): “Use-the-Nintendo-D-S.” Duh.
God bless devkitPro for providing an ARM9 c++ programming environment. Hooking the camera to the Gameboy cartridge slot took some figuring, but in the end it essentially involves strobing a pin connected through an optical isolation circuit to the camera’s cable release port. This method sacrifices the aperture control that using the Canon SDK allows when tethered to a laptop, however aperture is always the setting that never changes when taking HDR’s.
A funny cool thing happens once the camera is controlled by what is essentially a instant-on computer. Where the Canon 5D can do a bracket of three shots, spread two stops apart, and the latest 1DS MKIII series can do a nine shot bracket, the “DS-DSLR” can do any number of shots, and if I don’t like the way it does it, I can rewrite the software to do it better.
The DS can run in bulb-mode as well, so I can do automated exposures of several minutes beyond the thirty second limit of tethered laptop software, as well as allow for sensor cooling between bursts. This will come in handy when the Astrotrac I ordered from Richard Taylor at the P.A.T.S. show last week finally arrives from the U.K.
It also acts as a very precise intervalometer, which as Amazon kindly points out is a $120 value. But beyond just spacing out shots the timer can be set to run the bracketed exposure range at every timer interval instead.
The fun begins when you start to harness the play value of the DS in conjunction with the DSLR. This audio-based camera trigger function, for example, was trivial to add in, because of the DS’ built in microphone. One such device I found on the web sells for $350. As you can see I need to add a few niceties to this function, like the shot duration and an option for delaying the shot after the sound is recognized. I’m still in beta.
So here is the “first light” from the DS controlled camera. It was meant to be the start of a wide panorama, but when I finally noticed the tagger graffiti all around me, and the cars slowing to see what I was doing, I kinda got spooked and high-tailed it. This was a 16 shot range that was meant to expose for the full moon rising in the last frame of the pano.