CHDK overview

OK, take a deep breath and buckle in. It's time to delve into the shadowy world of CHDK or the Canon Hackers Development Kit.

I am a CHDK novice but I find it quite thrilling and subversive.
CHDK means different things for different users, but for me it means I can make my Canon S100 automatically shoot at set intervals by running an intervalometer script. I have mine set at one shot every 5 seconds. Perfect for KAP.

CHDK is a firmware hack that is loaded onto your SD card and over-rides the cameras firmware when it is turned on. It doesn't change the firmware permanently, just while that particular SD card is used and the camera is on.

The correct version or "Build" of CHDK must be downloaded from the CHDK website for your particular cameras firmware. Mine is S100-101b. They are not interchangeable.

Once CHDK is running on your camera you will see extra icons on the LCD. They can be quite ugly and obtrusive but the extra functions given to the camera make it worth while.

Initially it was conceived to give DSLR-like functions (RAW, live histogram, exposure bracketing) to compact cameras but it also allows scripts or mini programs to be run. The intervalometer script is the main reason I use CHDK.

The images below show how the camera screen changes when CHDK is loaded.

Here's my default Canon S100 screen and the normal Canon Menu

The SD card needs to be locked for CHDK to load up when the camera is turned on. This seems odd but that's how it works. With an unlocked card the camera just operates normally.

When CHDK is loaded correctly the splash screen appears first then the S100 screen appears with extra icons overlaid. It is possible move and hide the icons if you want but don't worry about that just yet.

To get to the CHDK menus you push the review button to change to <ALT> mode, then push the MENU button.

This is the Scripting Parameters screen where you choose a script. e.g. Intervalometer, and enter details like the interval e.g. 5 seconds

Now, as long as you are in <ALT> mode the Intervalometer will start when you push the shutter button and stop with another push.

Here's a video demo of CHDK.

That's it really. In the next post I'll cover how to find the correct build, download and copy to the SD card.