Canon Hacks – CHDK

Garden Folly in HDRWe’re Canon camera fans here, and besides owning a small “point-and-shoot” and a “superzoom”, I’ve been lusting after Canon’s latest high-end SLR, the EOS 5D MK II.  At 2 to 3 kilobucks however, it will be a while before I make that jump — we’ll need to extend the life of existing equipment.

The point-and-shoot, an A570 IS (7 megapixel images), makes great photos and has capabilities I hadn’t explored.  What else might it do?  I recently noticed two things: a little button near the bottom edge of the lens, and mention in a couple of articles that Canon cameras could be “hacked”.  The button was easy to learn about — it allows for the addition of extenders and other lens elements.  A quick trip to Amazon, and I was the proud possessor of a “wide-angle adapter” — extending the wide-angle capability of the camera all the way to a 24 mm focal length — almost a “fish-eye”.  What a great addition for landscapes!

The “hack” was even more interesting.  It seems that Canon has been using the same processor in most of their cameras for several years now, and exclusive of the lens and other physical characteristics of a given model, almost all of them can have very sophisticated capabilities.  Canon just didn’t choose to turn those features on in many cases.  I decided to give it a try.

It isn’t necessary (or wise) to reproduce all the steps needed to do this hack, because the CHDK site has everything you need to know.  Start here (CHDK in brief) and just follow the instructions.  As a preview though, you will:

  • see if your model is supported
  • check the firmware version of your camera
  • download the correct software version
  • install it on a memory card
  • and make a few settings (determined by how you want to use it)

It took me about 30 minutes from start to finish.  The hack adds a lot of new features like:

  • Save images in RAW format
  • Ability to run “Scripts” to automate the camera
  • Live histogram (RGB, blended, luminance and for each RGB channel)
  • Zebra mode (blinking highlights and shadows to show over/under exposed areas)
  • An “always on” full range Battery indicator
  • Ability to turn off automatic dark-frame subtraction
  • a higher compression movie mode, and double the maximum video file size
  • exposure times as long as 65 seconds
  • exposure times as little as 1/10,000 of a second
  • ability to use the USB port for a remote trigger input
  • a depth-of-field (DOF)-calculator
  • File browser
  • Text reader
  • ▪ Calendar
  • ▪ Some fun tools and games

This is only a partial listing however — I was most interested in “automatic exposure bracketing” — something I’ll talk about in another post.