>> Another question: When using slow synchro, is >> there a risk of fuzziness of the flashed image >> (the ambiance could be of course). Which is the >> duration of the flash? > >Flash duration varies depending on the individual flash >and the amount of light required for correct exposure, >but it's always brief enough to freeze almost anything. Well, at full power, a flash strobe is usually quite slow. Somewhere around 1/150s. Flash duration rapidly decreases with power (around 1/500s at 1/2 power, shorter than 1/10.000s for very slight flashes). This effectively very slightly decreases the available guide number when used with a high-speed sync cameras (1/250s or 1/300s), which is not a big deal. Consequently, a standard subject should be frozen by the flash if not too rapid, but a common speedlight cannot be used at full power to freeze fast action like water drops... Nicolas.
