Audible beep tone when flash fully recycled for 600EX-RT and ST-E3-RT
Tag: 600EX-RT, ST-E3-RT, C.Fn, Speedlite

Since the Speedlite 580EX II, Canon Speedlites have been using a new technology to enable silent recycling. However, some professional photographers reflected that incorporating an audible tone when flash recycling has completed will be useful in busy shooting conditions.

In Speedlite 600EX-RT, Canon has added a Customer Function C.Fn-20 to allow photographers to activate a “beep” tone when flash has fully recycled. The default setting of this customer function is “off”, we can enable this function on 600EX-RT or via the Speedlite Control menu in EOS Digital Camera*

Apart from 600EX-RT, Canon also added Custom Function C.Fn-20 in Speedlite Transmitter ST-E3-RT, this “beep” tone function is particularly useful for wireless multiple flash shooting. When “beep” tone is enabled, the master unit ST-E3-RT will give a single beep tone when all off-camera 600EX-RTs in all groups have recycled, similar to large studio flash. This is an easy way to avoid shooting before all slave units have recycled completely.

*Applicable to EOS Digital SLR cameras released from 2007 and onwards