Nikon Remote Triggering Oddities
I just recently got around to hooking up my camera to my Arduino-optocoupler triggering circuit and I discovered a small difference between how Nikon and Pentax cameras are wired. With the Pentax, I was able to close the 'focus' and 'shutter' circuits separately. I.e. When I was using my computer mouse trigger, I was able to right and left-click independently to focus and subsequently take a picture. With the Nikon, the focus circuit must be engaged before it will accept a shutter command.When you hit the shutter button on the camera body, you have to press *through* focus anyway, so you never notice the distinction. Likewise, on the Nikon remotes, there are two stacked leaf springs/cantilevered contacts that close the focus and shutter circuits. You have to push halfway to focus, and then even further to fire the shutter.My knock-off battery grip came with a Nikon-accessory-port-to-2.5mm-aux cable which makes it easy to work with individual contacts. It took a bit of jury-rigging to tie the contacts to my breadboard, but with the help of a 2.5-3.5mm converter cable and a 3.5mm jack, I was able to do it. I had a bit of trouble triggering my camera initially, and thought I had done something wrong, but when i went to unplug the 3.5mm plug from the jack, the right contacts were closed and I realized the problem wasn't with my optocoupler, but with the contacts on the aux cable.With a small, nondestructive modification to my cable, I solved the problem. I wasn't planning on focusing during a time lapse anyway... and yes. That's aluminum foil...So with triggering solved, and a stepper motor controller working (more on that on a later date...), I'm ready to put together something resembling a 1-axis motion control system. Stay tuned...