Capture pictures at set intervals
An intervalometer is a fancy device which enables a camera to take pictures at a set interval, creating a time lapse. In fact, it is so fancy, that many popular Canon cameras do not have this basic tool built-in. There is, however, a (cheap!) remote control which can trigger the shutter release on Canon DSLRs.
Pushing the button simply connects 2 pins together, which triggers the camera. By modifying the remote, the external electronics effectively ‘push the button’.
The resistors and capacitors determine all the timing: time on, time off, and the interval in between. And not too fast – both remote and camera need time to ‘see’ a change, then react.
The interval is adjusted by changing the resistor value between pin 7 and the 9V battery.
At minimum, there is a 330 ohm resistor which has an interval of 1.6 seconds. At maximum – 500k ohms – the interval is around 170 seconds.
This enclosure – a slightly modified transistor radio – houses and protects the electronics.
An added LED serves two purposes: it indicates the power is on, and also indicates the interval by blinking when a pic is taken.
Adjusting the tuning dial – which is now the resistor between pin 7 and 9V – selects the desired interval.
This time lapse demonstrates its potential.