This firmware update fixes/improves the following:
1. Added new functions for communicating with the Speedlite 580EX
2. Reduced noise when shooting bulb exposures
3. Fixed sensor-cleaning operations
This firmware supports cameras with firmware Version 1.0.1 or 1.0.2. If the camera already has the Version 1.0.3 firmware, this update is unnecessary.
Before downloading the firmware update, please be sure to read the entire contents of the following page.