A couple of days ago I stumbled over a 3.5 to 2.5mm audio jack adapter. Yesterday I finally had a couple of minutes to build a Canon remote control. I found out about it here, and it's pretty simple: All you have to do is build a switch to connect the tip of the jack to the sleeve - that focuses the camera and then releases the shutter.
Above the parts I used, to the right the result, and on the bottom myself trying it out the first time. Eventually I want to use a light barrier to photograph quick-moving stuff, but that will have to wait until after our holidays.
2 weeks ago