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Adjusting the flash output level of the remote flash units in the
w
(manual) mode
Adjusting the flash output level manually
Use the following equation to determine the proper manual flash output level of
the remote flash unit, depending on your creative preferences.
GN = F x D
where
GN
is the guide number of the remote flash unit (in meters/feet),
F
is the
lens aperture in use, and
D
is the distance between the remote flash unit and
the subject (in meters/feet).
For example, with the SB-800’s zoom-head position adjusted to 28mm when using an
ISO sensitivity of 100 if a lens aperture (F) of f/4 is used and the subject distance (D) is
2m (6.6 ft.) away, then shooting a subject at a distance of 2m (6.6 ft.), and a lens aperture
of f/4, then
GN (in meters)= 4 x 2 = 8
GN (in feet)= 4 x 6.6 = approx. 26
Therefore, to get the correct exposure, refer to the Guide Number table (p. 42) and adjust
the flash output level to M1/16.
• Refer to “Determining the aperture and flash output level in the Manual mode” (p. 42).
Adjusting the flash output level in Non-TTL auto flash (A); applicable when
using a Speedlight compatible with Non-TTL auto flash mounted on the
SU-4 as a remote flash unit
Non-TTL auto flash (A) can also be selected on the remote flash unit. In this
case, the remote flash unit controls the flash output based on the aperture and
ISO sensitivity set on the remote flash unit, and automatically stops firing in
sync with the master flash unit (p. 40).
1
Set the same ISO sensitivity on the remote flash unit as set on your
camera.
2
Set the same aperture on both the lens and the remote flash unit to obtain
the correct exposure.
• Depending on your creative preferences, you can intentionally overexpose or
underexpose the picture by modifying the aperture.
• The above setting is applicable ONLY when both the master and remote flash units
are pointed in the same direction.
• Refer to “Setting apertures in Non-TTL auto flash operation” (p. 41) for more details.
SU-4 type wireless multiple flash shooting