Kodak DCS600 User Manual
11-17
11
F
lash
Guide Numbers for Determining the Correct Aperture
Guide numbers help you determine a correct exposure or proper aperture (f/stop) when
using the SB-28D in the Manual
using the SB-28D in the Manual
or Repeating Flash
mode.
The guide number represents the amount of light at ISO 200 for meters/feet (m/ft)
generated by the flash. With the SB-28D, you can calculate a correct aperture or desired
flash shooting distance by using the following equations and the guide number table.
generated by the flash. With the SB-28D, you can calculate a correct aperture or desired
flash shooting distance by using the following equations and the guide number table.
Calculating the Correct Aperture
Calculating the Shooting Distance
Guide Number Table
Guide Numbers in meters/feet at ISO 200 in Manual and Repeating Flash modes.
Flash
Output
Level
Zoom-head position
18mm
20mm
24mm
28mm
35mm
50mm
70mm
85mm
1/1 (full)
25/84
28/93
42/139
45/148
51/167
59/195
68/223
71/232
1/2
18/59
20/66
30/98
32/105
36/118
42/138
48/157
50/164
1/4
12.7/42
14/46
21/69
22.5/74
25.5/84
30/98
34/112
36/118
1/8
9/30
10/33
15/49
16/53
18/59
21/69
24/79
25/82
1/16
6.4/21
7/23
10.5/35
11.3/37
12.7/42
15/49
17/56
18/59
1/32
4.5/15
5/16
7.5/25
8/26
9/30
10.5/35
12/39
12.7/42
1/64
3.2/10
3.5/11
5.3/17
5.7/19
6.4/21
7.5/25
8.5/28
9/30
M
f/stop (aperture) = Guide number
Flash shooting distance (m/ft)
flash shooting distance (m/ft) =
Guide number
f/stop (aperture)
f/stop (aperture)