22
Under low light when flash must be used, the following chart gives you the effective flash range for correct exposures for films
of various speeds. Note that high-speed film (ISO 400/800) extends your flash range significantly.
Effective flash range
Film speed
Wide angle (38 mm)
Telephoto(140mm)
ISO 100
0.9 – 2.8 m
0.9 – 2.0 m
3.0 – 9.2 ft.
3.0 – 6.6 ft.
ISO 400
0.9 – 5.6 m
0.9 – 4.0 m
3.0 – 18.4 ft.
3.0 – 13.1 ft.
ISO 800
0.9 – 7.9 m
0.9 – 5.6 m
3.0 – 25.9 ft.
3.0 – 18.4 ft.
ISO 1600
0.9 – 11.2 m
0.9 – 8.0 m
3.0 – 36.7 ft.
3.0 – 26.2 ft.
(Using color negative film)