This tip works great with Canon camera's. It requires you to install the software on the SD card and if you want the camera to return to it's original state. All you do is to remove the SD card.
The software overrides the camera's fireware settings but it can void your camera warranty, so make sure you understand the camera's warranty policy before you attempt to modify the camera's settings.
To confirm you have the new firmware installed on the camera just press Func Set and press the Disp button. A window should tell you the version of the firmware you have.
See compatible camera's
that work with this tweak.
You then will need to connect your SD card to a pc with a card reader to install the new firmware. Download and install Card Tricks
and choose the exact memory card you have and click on the SD icon and select your card. Click format as Fat and click Make Bootable and choose Download CHDK. A web page should open and select your camera and firmware version. Save the file to your desktop without extracting the file downloaded. In Card Tricks choose CHDK -> card and select the firmware file you downloaded. The software will transfer the file to the card without unzipping it. You now take the card and install it on to your camera. When you camera is powered on, it should go to a screen splash indicating that CHDK is running. Now you can access features beyond your spec's.
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Thanks for the tip www.PCWorld.com