Firmware Notice: Speedlite 600EX-RT and Speedlite Transmitter ST-E3-RT


Please see the changes to the "Identification Procedure" section below regarding criteria for affected serial numbers.  The identification method has been enhanced in order to more precisely identify affected products.

Firmware Notice

Thank you for using Canon products.


Except as described below, the following will occur with the affected units listed below:

Linked shooting and wireless flash shooting with radio transmission will not work in some setting modes when 7 or more units are linked. This phenomenon does not occur when 6 or fewer units are linked.

Affected Products

Speedlite 600EX-RT and Speedlite Transmitter ST-E3-RT

Units with a combination of 3rd and 4th digits in the serial number in the ranges shown below are affected:

  • Speedlite 600EX-RT:                            [xx01xxxxxx] ~ [xx12xxxxxx]
  • Speedlite Transmitter ST-E3-RT:           [xx01xxxxxx] ~ [xx03xxxxxx]

Note:  If the battery compartment of an affected unit contains the marking illustrated below, the product is NOT affected by the phenomenon described above, even if the serial number is within the ranges mentioned above.


Product Advisories - Speedlite 600EX-RT

To arrange to have an affected unit inspected and serviced for this phenomenon at no cost, please contact Canon using the information below.

This information is for residents of the United States and Puerto Rico only. If you do not reside in the USA or Puerto Rico, please contact the Canon Customer Support Center in your region.

Thank you for using Canon products.

Customer Support Operations
Canon U.S.A., Inc

Contact Information for Inquiries
Canon Customer Support Center
Phone:    1-800-OK-CANON     
TDD:      1-866-251-3752
For additional support options:

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