Submitted by Marty on Sat, 01/08/2009 - 17:04
My Camera
My own DSLR is a Pentax K10d, which weighs 785g (including battery but without a lens). The shutter and auto focus can be fired remotely via a cable release or the shutter via IR remote. Various in camera settings can be set to help, such as one-press-one-shot, mirror lock up, etc.
A while ago I made a home-made cable release. This worked, but never worked well as I soldered it using a cigarette lighter (I was overseas away from my tools at the time). However, I can easily hack it to hook it up to a microcontroller.
Camera/Controller Interface
Although relays could be used, it appears opto-isolators are the better solution. They require less current, have no moving parts and no (or negliable) back EMF, unlike a relay which generates EMF as the magnetic field collapses when switched off. Luckily I found some 4N25 opto-isolators amoungst the electronics stuff at home. Although I had trouble getting them to work (two of three were damaged) they did in the end.
The following video was taken with the camera (on manual settings) being fired every 30 seconds by the PICAXE;
Most Viewed Image
Backyard Timelapse Test 4
Date: 01/08/09 Views: 1036
The PICAXE was running off mains power, the camera was not. It took about 400 frames before the battery ran out.
However, the ability for the microcontroller to fire the shutter being achieved (the same wiring can be duplicated for autofocus), this part of the project is done for now.