I’ve fixed the E18 Error on my PowerShot SD450 and posted the steps here:
E18 Error Fixed! (Canon PowerShot SD450)
Found this site when I began to research the error which mysteriously began appearing on my Canon PowerShot SD450 (and luckily *not* on my Canon 30D), which explains what seems to be a pretty prevalent error within the PowerShot series:
This web site’s mission is to provide a source of information and help for the Canon E18 Error.
The E18 seems to be a significant flaw in an otherwise great camera.
It is a flaw well know by users of Canon Powershot and Ixus cameras and is currently not acknowledged by Canon as a flaw in camera design.
HOW IT ALL WORKS:
Canon E18 error happens when the lens gets stuck while trying to extend. The camera will beep a few times and the LCD will display a little E18 in the lower-left corner. The lens gets stuck in the extended position, and refuses to move either to focus the lens or to retract when powered off.
Apparently, people who posted about this incident on forums say they had to send the camera for repair and that Canon has horrible customer support and response time.
Here is how the E18 error looks like. You just get a black screen with small “E18” sign in the lower-left corner:
The problem usually happens because dirt or sand get into the lens mechanism. But it seems that more and more people are showing, who took great care of their camera, and still started receiving E18 errors.