GODOX TT685II-C Flash for Canon Speedlight Camera Flash E-TTL Speedlite High-Speed Sync, 2.4G Wireless X System Compatible for Canon Flash 5D Mark IV 6D Mark II 7D 90D 250D R5 850D (Upgraded TT685C) 4.7 out of 5 stars 91
600EX-RT - This is Canon's flaship flash. It can be a trigger or slave. It can also work optically or via radio. It also has a focus-assist beam builtin. 90EX - This is a very small, low power flash, but it can function as an on-camera master to trigger a remote slave flash. GODOX TT685II-C Flash for Canon Speedlight Camera Flash E-TTL Speedlite High-Speed Sync, 2.4G Wireless X System Compatible for Canon Flash 5D Mark IV 6D Mark II 7D 90D 250D R5 850D (Upgraded TT685C) Godox V860III-C Camera Flash for Canon Camera Flash Speedlite Speedlight Light,2.4G HSS 1/8000s,480 Full-Power Flashes,7.2V/2600mAh Li-ion BatteryThe 430EX III-RT has both radio wireless capability and optical wireless capability as a "Slave Flash", but only radio wireless capability as a "Master Flash". The 270EX II has only optical wireless capability as a "Slave Flash", just as the 430EX II in the chart shown in the manual.
In reply to M Schneider β’ Nov 23, 2020. Yes, you can control it with the optical wireless system, and it does have a provision for just the external remote flash to fire to light the subject. Download the 90D manual from Canon. canonaimer's gear list: Pentax K-5 IIs Canon EOS 6D Canon EOS 7D Mark II Canon EOS 5DS Pentax K-3 II +38 more. Reply