> Not necessarily. For examply my old slave trigger is not so sensitive. > It's going to be difficult to get the ETTL preflash to set it off. And > of course it depend on how it's pointed and how much light it > receives. > And since it's light is strictly for the background, it's not really > going to affect exposure, or at least it'll be a consistantcy one can > work with. > Depend on how one is metering. ETTL is a funny thing sometimes as are > all TTL systems. That' why I like the 550EX. I can use manual power > and no preflash. Sometimes ETTL is not the answer, like in a studio > portrait. It's just not needed.
Hi Jim, You are lucky with your slave triggers. The E-TTL 1/32 power preflash is enough to set off my cheap not-so-sensitive optical slave trigger indoors, even from reflected light. When you take a shot, the interval between E-TTL preflash and exposure flash is just long enough for the background light to discharge, but not long enough for it to recharge. Result: dark backgrounds :-( Of course, there is no preflash if you use a 550EX in MANUAL mode. Although there appears to be also no preflash (with the mirror down) when using a 550EX as E-TTL wireless master in manual mode, there is still some clever way that Canon found to encode channel and group information that I have not been able to figure out. So, there is more to E-TTL than just preflash automatic metering. With wireless E-TTL, you can adjust manual power levels for up to three flash units without stepping away from your camera: i.e. [t: m/2, m/4, m/8] -> [t: m/4, m/2, m/16] Cheers Julian Loke * **** ******* *********************************************************** * For list instructions, including unsubscribe, see: * http://www.a1.nl/phomepag/markerink/eos_list.htm ***********************************************************
