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HIGH RESOLUTION By Balakumar
Balasubramaniam
TIME-LAPSE MOVIES USING A
STILL CAMERA
Making time-lapse movies is child's play these days as many camcorders
come factory equipped with features that allow you to take pictures
periodically once every few seconds. The pictures can then be assembled
using a freeware like Windows Movie Maker. But, there is one major
limitation to taking this approach for time-lapse movie making: the poor
resolution of most inexpensive camcorders. What if you wanted to take a
time-lapse movie with a 6 megapixel resolution per frame? Alternately, have
you ever been the designated photographer of the party and wished your
camera could automatically click away the celebrations from a vantage point
while you enjoy the party?
Enter Cam Tim! Cam Tim is a digital camera hack that
will convert your digital camera into a high-res time-lapse camera. The hack works the simplest if the camera
has a single button trigger. You can select the inter-frame
interval from a few seconds to a few hours with hardware
switches and your camera will click away for eternity. And
best of all, building the entire circuit on a RadioShack
breadboard will cost less than $30!
The Hack
There are two main components to complete before
we get all this to work. First, we’ll hack the camera trigger
to allow external triggers. Then, we’ll build the external
trigger circuit. Let’s get started with the trickiest one first!
The Camera Trigger
All cameras work the same way: Press a button and
the camera will snap a picture. Our hack works by
handing over the button-press part to a microcontroller.
The first step is to figure out where the buttons of the
remote or the camera terminate on the respective (printed
circuit boards). In Figure 1, we show the remote controller
of an Olympus C5000-Zoom camera and the location of
the button terminals. Solder a 9V battery connector to the
terminals, bring the terminals out of the remote control's
body as shown, and seal the remote once again.
The Trigger Circuit
Next , when the button terminals are electrically
closed, the camera will take a picture. (It goes without
saying that if you are hacking a remote control, the IR
LEDs should point towards the camera!) In this project, we
use a mini-relay to electrically close the terminals from
step 1 (Figure 2). The relay is driven by one of the pins
■ FIGURE 1. Wiring the remote for external trigger.
February 2009 41
