Univex SB-900 user manual D–54, Adjusting the flash output level manually

D

Flash modes and functions

SU-4 type wireless multiple flash shooting

tAdjusting the flash output level of the remote flash units in the M (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 × 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-900’s zoom position adjusted to 18 mm, using an ISO sensitivity of 100, standard illumination pattern, in FX-format, shooting a subject at a distance of 2 m (6.6 ft.) with a lens aperture of f/5.6, then

GN (in meters)= 5.6 x 2 = 11.2, or GN (in feet)= 5.6 x 6.6 = approx. 37. Therefore, to get the correct exposure, refer to the Guide Number table (kF-19) and adjust the flash output level to M1/4.

•Refer to “Determining the aperture, flash output level and flash shooting distance in the Distance-priority manual and Manual flash mode” (kD-22).

■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 (optional)

•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 (kD-8).

Set the same ISO sensitivity on the remote flash unit as set on your camera. 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 face the same direction.

•Refer to “Flash shooting distance range” (kF-16) for more details.

D–54