any other camera off the shelf. It’s highly unlikely that
using CHDK can physically harm your Canon — except
maybe if you’re driving the lens focus mechanism while
the camera is against a wall — so CHDK is a safe way to
modify the functioning of a camera.
Many volunteers have developed and expanded
CHDK over time. As new camera models become
available, volunteers port new versions of CHDK for these
cameras. To download the Canon Hacker Development
Kit, go to its Wiki site at http://chdk.wikia.com/wiki/
MY EXPERIENCE WITH CHDK
I found a reasonably priced Canon A550 on the
Internet to use to learn about CHDK. Before actually
purchasing the camera, I made sure there was a CHDK
version for the PowerShot A550. The CHDK Wiki site
comes in handy here, as it lists the currently supported
camera models. After receiving the camera and a new 2
GB SD card, I followed these steps to verify my A550 had
the correct firmware version for the copy of CHDK I
■ CHDK splash screen.
the version I downloaded and found it was designed for
a Canon PowerShot A550 with version 1.00C firmware.
• Inserted the SD card into a PC, clicked My Computer,
and formatted the SD card.
• Started Notepad, but before typing anything, named
and saved the blank file by clicking File, then Save As.
• In the Save As window, selected All Files.
• Gave the file the name ver.req and saved it in the root
of the formatted SD card.
• Repeated this a second time with a file name of
Note: ver.req means version required. Some Canon
cameras require a file named ver.req to report the firmware
version and others require a file named vers.req. Just to be
certain I had the correct file name, I saved both files on
the SD card.
• Removed the SD card from the PC and loaded it into
the Canon A550.
• Started the camera in play mode.
So far, so good. My new camera read the file I saved
on its SD card and gave me the version and date of its
firmware in response. The CHDK Wiki actually suggests
following this procedure before you purchase a new
Canon. So, prepare an SD card as I described above and
take it to the camera store. There, get permission to load
the SD card in a camera and check the camera’s firmware
version before you purchase it.
Now it was time to prepare the SD card for installation
of CHDK. You can install all the files yourself or use an
application called Card Tricks which is what I did. Back at
the CHDK Wiki, I found the Card Tricks program and the
CHDK version for my Canon A550. I installed Card Tricks
on my PC and unzipped the files in a directory on the
hard drive where I would remember where I put them.
To install CHDK, the SD card must be removed from
the camera and inserted into the PC's card reader. Note,
you cannot install CHDK by leaving the SD card in the
camera and attaching the camera to the PC with its USB
cable. You must remove the SD card and install CHDK
directly through the PC. The USB cable lets you view and
Note: Check your camera’s directions,
but my A550 uses the upper left button to
toggle between play and photograph.
• Held the FUNC.SET button and then
pressed the DISP button.
• Observed the LCD screen as it displayed
the firmware version and a date
(my camera’s details were GM1.00C
4 Dec 2006).
• Checked the CHDK documentation for
■ These are the buttons I use on my Canon
PowerShot A550. Other Canons use similar
buttons, but their locations may vary.
September 2010 69