Nikon SB-500 AF Speedlight - Manual (Page 86)

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Tips on Speedlight Care and Reference Information
Specifications
Guide number table
The SB-500 guide numbers differ depending on the camera’s ISO
sensitivity and flash output level.
ISO 100; m/ft
Flash output
level
1/1 1/2 1/4 1/8 1/16 1/32 1/64 1/128
Guide number
24/
78.7
16.9/
55.4
12/
39.3
8.4/
27.5
6/
19.6
4.2/
13.7
3/
9.8
2.1/
6.8
Guide number table (for auto FP high-speed sync)
ISO 100; m/ft
Flash output
level
1/1 1/2 1/4 1/8 1/16 1/32 1/64 1/128
Guide number
10.1/
33.1
7.1/
23.2
5.1/
16.7
3.6/
11.8
2.5/
8.2
1.8/
5.9
1.3/
4.2
0.9/
2.9
• Guide numbers in the above tables are for when the SB-500 is used
with a D4 camera with a 1/500 sec. shutter speed.
• Guide number for auto FP high-speed sync varies depending on
the camera’s shutter speed. For example, when the shutter speed
is changed from 1/500 sec. to 1/1000 sec., the guide number
decreases 1 step. The higher the shutter speed, the smaller the
guide number.