Technical data

unit or a flash gun.
Shutter Speed Setting for Flash Exposure
Shutter Speed 1/60 1/30 1/15 1/8 1/4 1/2 1
Electronic Flash O O O O O O O
Flashbulb FP O O O O O O
M O O O O O O
MF O O O O O O
Correct Exposure Setting in Flash Exposure
Correct exposure in flash photography is determined on the basis of the
guide number of the electronic flash unit or flashbulb in use. To obtain the
aperture setting ensuring correct exposure, divide the guide number of the
electronic flash unit or flashbulb in use by the flash-to-subject distance (in
feet or meters).
(Guide Number Flash-to-Subject Distance = Correct Aperture) When the