Nissin AIR 10S Instruction Manual page 19

M. Zoom
Since the different focal length of the lens are suitable for different angles
of the shooting range, the focal length is getting shorter at the same sensors size.
Which means that the smaller focal length lens with larger angle in the view,
the flash area coverage will be larger.
Nissin i60A Guide No. at manual exposure mode (ISO 100 in meters)
Zooming
Position
Full
24mm
27
28mm
29
35mm
32
50mm
39
70mm
42
85mm
45
105mm
50
135mm
54
200mm
60
For the camera system we support, there are 4 main image sensor sizes:
35mm Full Frame format, APS-C format, 4/3 system format and 1" sensor format.
The effective focal length of the mounted lens varies depending on the camera's
image sensors size. Air 10s recognizes the image sensor size of each camera sensor format
automatically , users can use auto or manual mode to adjust the optimum flash coverage of
the slave units and make the effective focal length of lens within a range of 24-200mm.
Flash Power Level (Guide No.)
1/2 1/4 1/8
19 13 10
20 14 10
23 16 11
28 20 14
30 21 15
32 23 16
36 25 18
38 27 19
42 30 21
1/16 1/32 1/64
7 5 3
7 5 4
8 6 4
10 7 5
11 7 5
11 8 6
13 9 6
13 10 7
15 11 7
1/128 1/256
2 2
3 2
3 2
3 2
4 3
4 3
4 3
5 3
5 4
18