A refined lightweight flashgun with power and capabilities that belie its compact frame canons speedlite 430ex iii rt improves on prior models with an enlarged display screen simplified controls and the introduction of radio based wireless ttl previously the remit of the much higher priced 600ex rt the 430ex iii rt also boasts optical triggering a guide number of 43 with 24 105mm coverage movable head with integral reflecting panel and a 32s cycle time all in all on or off camera the