Samsung SEF-36PZF User Manual page 27

Guide Number (GN)
Guide numbers indicate flash light intensity. The
larger the number, the farther you can reach with
your flash. From the guide number, you can easily
obtain the proper aperture setting required for an
optimum exposure.
가
Aperture [f-number] =
GN
GN/flash-to-subject distance
이드 넘버 25
《27》