Speedlights

[jonesblmm]

Is it possible to use a 600 EXII RT as a master and a 430 EXII-RT as a slave without adding a trigger system? Will the 600 be able to control the 430?

[rs-eos]

Did you mean to say "430 EXIII-RT" (3rd-generation 430?)   If so, the 600-series flash should be able to trigger the 430 in either radio mode or optical-line-of-sight mode.  If you have the 2nd-generation 430, you'll need to use the optical mode.

[jonesblmm]

Thank you!