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Flash Photography
April 29, 2004 10-5
Flash Shooting Distance
Range for the Built-in
Speedlight
The flash shooting distance range varies, depending on ISO and aperture.
ISO 200 400 800 1600 Flash shooting
distance range (m)
Guide number 17 24 34 48
Aperture value 2 2.8 4 5.6 2 - 8.5
2.8 4 5.6 8 1.4 - 6
45.68 11 1 - 4.2
5.6 8 11 16 0.7 - 3
8 11 16 22 0.6 - 2.1
11 16 22 32 0.6 - 1.5
16 22 32 — 0.6 - 1.1
22 32 — — 0.6 - 0.8
You can also calculate the maximum flash shooting distance by dividing
the guide number by the aperture value.
For example, with an aperture of f/2.8 and an ISO of 200, the maximum
flash shooting distance will be 17 / 2.8 = approximately 6 m.