Nikon Speedlight SB-600 User Manual
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Determining the aperture and flash output level 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)
Flash output
Zoom-head position (mm)
level
14*
24
28
35
50
70
85
M1/1
14.0/45.9
26.0/85.3
28.0/91.9
30.0/98.4
36.0/118.1
38.0/124.7
40.0/131.2
M1/2
9.9/32.5
18.4/60.4
19.8/65.0
21.2/69.6
25.5/83.7
26.9/88.3
28.3/92.8
M1/4
7.0/23.0
13.0/42.7
14.0/45.9
15.0/49.2
18.0/59.1
19.0/62.3
20.0/65.6
M1/8
4.9/16.1
9.2/30.2
9.9/32.5
10.6/34.8
12.7/41.7
13.4/44.0
14.1/46.3
M1/16
3.5/11.5
6.5/21.3
7.0/23.0
7.5/24.6
9.0/29.5
9.5/31.2
10.0/32.8
M1/32
2.5/8.2
4.6/15.1
4.9/16.1
5.3/17.4
6.4/21.0
6.7/22.0
7.1/23.3
M1/64
1.8/5.9
3.3/10.8
3.5/11.5
3.8/12.5
4.5/14.8
4.8/15.7
5.0/16.4
* With the wide-flash adapter in place
To calculate the correct aperture
Calculate the correct aperture by using this equation and the guide number
table, according to the flash output level, zoom-head position and ISO
sensitivity set on the camera:
• Set this aperture on the camera or lens.
To calculate the guide number
Calculate the guide number by using this equation, according to the shooting
distance and aperture required.
• Referring to the guide number table, determine an appropriate flash output level
corresponding to the guide number obtained above, then set the same value on the SB-600.
ISO sensitivity factors
For sensitivities other than ISO 100, multiply the guide number by the factors
shown in the table below.
ISO
25
50
100
200
400
800
1600
Factors
x0.5
x0.71
x1
x1.4
x2
x2.8
x4
Guide number (GN) = Shooting distance (m/ft) x Aperture ÷ ISO sensitivity factor
f/stop (aperture) = guide number (GN) x ISO sensitivity factor ÷ Shooting distance (m/ft)
Detailed oper
ation