Canon Inc. has resumed offering a web download service for EOS 20D Firmware. As mentioned yesterday, the version number has been changed to 1.0.5. The web address for this download remains the same as it was before:

For more details, please review the following text, which has been reproduced from Canon Inc.'s web site:

EOS 20D Firmware Update Version 1.0.5
Firmware specification changes

We have discovered that the version 1.0.4 firmware released on October 4 had a bug in the program that handles the update. In cases where the update was performed with a lens attached to the camera, there were situations in which the firmware could not be updated correctly.

In cases where the firmware was not updated correctly, the camera might not power on, the camera might not communicate properly with the lens and flash, or similar malfunctions might occur.

Canon offers its sincerest apologies to customers who have been inconvenienced by this situation.

Even for customers who successfully updated to the version 1.0.4 firmware without incident, Canon recommends updating to the new version 1.0.5 firmware for the sake of certainty.

Note: The bug described has been fixed in the version 1.0.5 firmware, but please remove the lens from the camera when performing this update.

Customers who were unable to update their camera's firmware from version 1.0.2 to version 1.0.4, or those who performed the update only to find that the camera would not power on afterward, please contact the service center listed on the service information that came packaged with your EOS 20D.

Canon would like to express once again its apologies to all customers who were affected by this situation.

Please note that the actual firmware content of versions 1.0.4 and 1.0.5 is the same. If your EOS 20D already had the version 1.0.4 firmware when you purchased it, there is no problem with leaving it as is. There is also no problem if you choose to update the firmware to version 1.0.5, but the content of the firmware is the same for both versions.

This firmware update applies to cameras with firmware versions 1.0.4 or earlier. It is not necessary to perform this update on cameras that already have version 1.0.5 firmware.


When the firmware update operations are finished, turn the camera off and remove battery from the camera for at least two seconds. This will cause the new firmware to effect after the battery has been reloaded and the camera is turned on.

When performing the firmware update operations, do so after removing the lens from the camera.

Please read this page in its entirety before making use of the download service.

October 2004Technical documentation