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Other functions
Guide number in Auto FP High-Speed Sync (ISO 100, m/ft)
Flash output
Zoom-head position (mm)
level
14* 24 28 35 50 70 85
M1/1 3.9/12.7 7.2/23.6 7.8/25.5 9.0/29.5 10.2/33.4 11.4/37.4 12.0/39.3
M1/2 2.7/9.0 5.0/16.7 5.5/18.0 6.3/20.8 7.2/23.6 8.0/26.4 8.4/27.8
M1/4 1.9/6.3 3.6/11.8 3.9/12.7 4.5/14.7 5.1/16.7 5.7/18.7 6.0/19.6
M1/8 1.3/4.5 2.5/8.3 2.7/9.0 3.1/10.4 3.6/11.8 4.0/13.2 4.2/13.9
M1/16 0.9/3.1 1.8/5.9 1.9/6.3 2.2/7.3 2.5/8.3 2.8/9.3 3.0/9.8
M1/32 0.6/2.2 1.2/4.1 1.3/4.5 1.5/5.2 1.8/5.9 2.0/6.6 2.1/6.9
M1/64 0.4/1.5 0.9/2.9 0.9/3.1 1.1/3.6 1.2/4.1 1.4/4.6 1.5/4.9
M1/128 0.3/1.1 0.6/2.0 0.6/2.2 0.7/2.6 0.9/2.9 1.0/3.3 1.0/3.4
* With the wide-flash adapter in place
• The guide number in Auto FP High-Speed Sync above is applicable when the shutter
speed is set at 1/500 sec.
• The guide number in Auto FP High-Speed Sync above varies according to shutter
speed. For example, when the shutter speed changes from 1/500 sec. to 1/1000 sec.,
the guide number decreases by 1 EV. This means that the higher the shutter speed, the
lower the guide number.
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 0.5 0.71 1 1.4 2 2.8 4