I just got a Sigma EF500 Super and got some queries on using a ETTL flash.
(a) When I do bounce-flash (ceiling bounce or card bounce), do I have to compensate the flash positively? Or will the ETTL system automatically compensate for me?
(b) When I want to do fill-flash (in Av mode), should I compensate the flash negatively? Or again, will the ETTL system automatically compensate? I remember in many of the zoo shots, fill flash was set at -1 compensation. Is this value of -1 a rule of thumb, or must it be determined by experience?
thanks for any replies!