... second time Flash. S3:Continous-flash function,Camera Hotshoe Flash,IR Flash,X line Flash, Hand Flash,Wireless ... Everytime can flash 5 times. S4:Continous-flashfunction,Camera Hotshoe Flash,IR Flash, X line Fash, Hand Flash, ... the manual test.Using Filter: You can use the 4 pieces of filter to adjust the angle ... the perfect exposal.Or can use the color filter to adjust the color temperature you need.FM ...