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“Photo grandpa” builds mother of all homebrew laser triggers

A reader who saw Marc’s recent post about an Arduino-controlled laser photo trigger wrote in to tell us about the amazing work of Belgian photographer and Flickr user fotoopa (which, we hear, as “foto opa,” means something like “photo grandpa” in Dutch). That’s him in the picture above, with the awesome homebrew laser-triggered camera rig that he uses to capture amazing pictures of insects in flight and splashing drops of colored water. I’m generally skeptical of film purists, but fotoopa makes the compelling claim that no digital camera has the shutter speed necessary to do this kind of imagery. He claims the Compur #1 shutter used in his 2008 setup has a speed of less than 5 milliseconds. Technical details about his 2009 setup are available here. [Thanks, Wilco Schillemans!]

14 thoughts on ““Photo grandpa” builds mother of all homebrew laser triggers

  1. He is actually using a digital camera (D200) with a mechanical shutter from an old film camera hacked on to the front of it. What he does is put the camera in “bulb” mode to lock the internal camera shutter open, and then use this external shutter to actually take the pictures.

    It’s a pretty wild setup- interesting post.

  2. Very impressive setup.

    5 msec is 1/200th of a second which doesn’t seem like that
    fast a shutter to me.

    Just an FYI…
    Using a Canon with CHDK you can apparently get sub mili sec shutter speeds.

  3. The shutter used is a Compur (used in large format photography), which is a diaphragm type that opens up all the way and then closes down again. Modern SLRs use a curtain type, that actually employs two curtains at high speeds, effectively creating a traveling slit of light that flashes in front of the film/sensor to expose it. The diaphragm shutters offer faster flash sync speeds than the curtain type, though Nikon has made a strobing flash workaround, but there are other advantages to the diaphragm type as well. A serious disadvantage is that the shutter resides in the lens, so that every lens has to have its own shutter for such a camera to work.

  4. Looking at the explanation on flickr, I see why he’s using the leaf shutter. It’s not the shutter speed that he’s worried about, nor the sync speed, but it’s the shutter lag. The bugs move fast enough that if you have a 100ms or even 50ms shutter lag, they’re out of the frame. The compur can be driven much more quickly than that so that the lag is 5ms, (or 7 in the current version) and the insect doesn’t get a chance to leave the frame. the motion capability is from running his flashes at 1/64, which should be about 1/20000th of a second or so.

    1. Correct! The shutterlag is the most critical time to capture insects in-flight. Freezing the action is done by the 2 flashes at low power to freeze as much as possible the fast moving wings.

      But the most hightech part is the auto detection by IR laser signals and an extra detector macro lens with integrated AVR controller to measure the reflected IR signal. This signals are send 20 usec on- 20 usec off. Both signal levels on the detector lens are calculated via the ATtiny45 controller and send every 40 usec to the FPGA module. The difference between environment light and IR light gives the values for the FPGA controller. The 2 IR lasers are on the side and pointed to the ideal focuspoint. The reflected IR signals are only possible if an object is correct into the focuspoint. A few mm out this point set the IR signal to zero. By this way the insects are detected into 40usec delay only. Information from the AVR controller is send via SPI signals to the FPGA module. The FPGA module works on 50MHz to drive all the timings digital at very precise delays.


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I am descended from 5,000 generations of tool-using primates. Also, I went to college and stuff. I am a long-time contributor to MAKE magazine and My work has also appeared in ReadyMade, c't – Magazin für Computertechnik, and The Wall Street Journal.

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