Flash Effective Range - Samsung SEF-54PZF User Manual

FLASH EFFECTIVE RANGE

■ Calculating the Flash Effective Range
When setting the lens to manual f/stop, calculate
the guide number at main flash with the use of
flash's zoom position and ISO. Divide the resulting
guide number by the aperture in use. Thus, the
maximum distance is obtained. The minimum dis-
tance is obtained in dividing this max. distance by
approx. 10.
[Example] :
With a 85 mm lens at f/4 and sensitivity at ISO100
① For the zoom position 85mm and sensitivity at ISO100, the guide number is 54.
② 54 (guide number) /4 (aperture) = 13.5m (max. distance)
③ 13.5m (max. distance) /10 = 1.35m (min. distance) Thus, flash effective range is approx. 1.35m - 13.5m.
However, if the minimum distance obtained is 0.7m
or less, the minimum distance will be 0.7m. Refer
to page 59 for the guide number table.
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