Nikon SB-800 Marine Instruments User Manual


 
42
Manual mode
Manual mode
The SB-800 features three manual modes.
Distance-priority manual flash p
Manual flash G
Repeating flash q
You can calculate the correct aperture by using the guide number table and
the shooting distance. Then set the same aperture manually on the lens.
In this case, set the camera’s exposure mode to Aperture-Priority Auto (A) or
Manual (M).
Refer to your camera’s instruction manual for details on camera and lens aperture
settings.
•With the SB-800 in the Manual mode, if the camera’s exposure mode is set to other than
Aperture-Priority (A) or Manual (M), the shutter may not be released, depending on the
cameras in use. For details, refer to your camera’s instruction manual.
In the Manual mode, no warning ready-light blinks to indicate that the light may have
been insufficient for correct exposure after shooting.
Determining the aperture, flash output level and shooting distance in
the Manual mode
In the Manual mode, use the guide number table and the following equation to
calculate the aperture, flash output level, and shooting distance to obtain the
correct exposure.
The guide number (GN at ISO 100; m/ft) indicates the amount of light generated by
the flash. The larger the number, the greater the flash output.
Guide number (ISO 100, m/ft)
*1 With the Nikon Diffusion Dome attached and the wide-flash adapter in place
*2 With the Nikon Diffusion Dome attached
*3 With the wide-flash adapter in place
Zoom-head position (mm)
1 2 14
3
17
3
24 28 35 50 70 85 105
M1/1 12.5/41 16/52 17/56 19/62 30/98 32/105 38/125 44/144 50/164 53/174 56/184
M1/2 8.8/29 11.3/37 12/39 13.4/44 21.2/70 22.6/74 26.9/88 31/102 35.4/116 37.5/123 40/131
M1/4 6.3/21 8.0/26 8.5/28 9.5/31 15.0/49 16/52 19/62 22/72 25/82 26.5/87 28/92
M1/8 4.4/14 5.7/19 6.0/20 6.7/22 10.6/35 11.3/37 13.4/44 15.6/51 17.7/58 18.7/61 19.8/65
M1/16 3.1/10 4.0/13 4.3/14 4.8/16 7.5/25 8.0/26 9.5/31 11/36 12.5/41 13.3/44 14/46
M1/32 2.2/7 2.8/9 3.0/10 3.4/11 5.3/17 6.0/20 6.7/22 7.8/26 8.8/29 9.4/31 9.9/32
M1/64 1.6/5 2.0/7 2.1/7 2.4/8 3.7/12 4.0/13 4.8/16 5.5/18 6.3/21 6.6/22 7.0/23
M1/128 1.1/4 1.4/5 1.5/5 1.7/6 2.6/8.5 2.8/9 3.4/11 3.9/13 4.4/14 4.7/15 4.9/16
Flash
output
level