The Canon Speedlite 600EX II-RT is Canon’s flagship hot shoe flash and update to the Canon Speedlite 600EX-RT. Key features include:
Faster, longer-lasting continuous-flash performance
New flash-readiness indicator
Simplified button and dial operation
Built-in 2.4 Ghz radio receiver
What’s New? The 600EX II-RT offers faster, longer-lasting continuous-flash performance, a flash-readiness indicator, simplified button/dial operation, improved weather-sealing, and new accessory modifiers.
Built-in 2.4 Ghz Radio Receiver. Unchanged from its predecessor, the 600EX II-RT gives you wireless triggering of 600EX-RT, 430EX III-RT, and other 600EX II-RT flashes at distances up to 98.43 feet without line-of-sight. There’s also an optical pulse triggering method for when you’re working with older-generation flashes.
Output and Operation. With the exception of continuous-flash firing, the output also remains unchanged from the 600EX-RT. You still have a 24-200mm (full-frame equivalent) zoom range, 14mm wide panel, and flash output of GN:197’ @ ISO 100/200mm.
Accessories Included! New to this updated version are included hard-type bounce and color-filter adapters. Along with the flash, all this fits in a less-camera-bag-friendly pouch. Sorry!
Functionality. Similar story here—not too much has changed. You’ve got the same tilt and swivel capabilities (-7º to +90º/360º). As mentioned above, there’s now a flash-readiness indicator and improved combination button/dial operation. The flash is powered via four AA batteries (not included!) or an external battery pack like the Canon CP E4N.
Speaking of batteries: