High Speed Flash Diagram from Canon Flash Work
Normal flash requires a synchronizing shutter speed or below. In a synchronizing shutter speed, the first curtain travels to a fully open position, at this point the flash is triggered and extinguishes before the second curtain follows. When a photograph is taken with a high shutter speed with a normal flash the result will be a partial picture.
Flash is possible with extremely high shutter speed with a setting on Canon Flash that is called – High Speed sync. High speed sync modes actually are a very fast strobo cycle that paints the exposure as the narrow slit of the focal plane shutter curtain races across the sensor.
Here is an excellent resource for Canon Flash
I just order the new Pocket Wizard
Mini TT1 and Flex TT5: TTL Radio Triggers
These radio slaves will open up a world of radio controlled High Speed TTL flash in bright ambient lighting situations where the built in optical communication between flashes would be difficult.
I am thinking about a 580 flash mounted in a softbox used in full TTL – HS flash at 1/4000 sec at f/2.8.
