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FP MANUAL
The following guide number figures have a 1/1 flash intensity ratio.
ZOOM (mm)
Shutter speed
The guide numbers for flash intensity ratios other than 1/1 in the FP MANUAL mode
can be calculated with the following formula.
Guide number = Guide number at 1/1 × Flash intensity ratio coefficient
Flash intensity ratios and their coefficients
46
EN
FOUR THIRDS
8
With 135
16
1/125
13
1/160
11
1/200
10
1/250
9.0
1/320
8.0
1/400
7.1
1/500
6.4
1/640
5.7
1/800
5.0
1/1000
4.5
1/1250
4.0
1/1600
3.6
1/2000
3.2
1/2500
2.8
1/3200
2.5
1/4000
2.2
1/5000
2.0
1/6400
1.8
1/8000
1.6
Flash intensity ratio
Coefficient
10
12
14
17
20
24
28
35
14
20
21
26
13
18
19
23
11
16
17
20
10
14
15
18
8.9
13
13
16
7.9
11
12
14
7.1
9.9
11
13
6.3
8.8
9.4
11
5.6
7.9
8.4
10
5.0
7.0
7.5
9.0
4.4
6.2
6.7
8.0
4.0
5.6
5.9
7.2
3.5
5.0
5.3
6.4
3.1
4.4
4.7
5.7
2.8
3.9
4.2
5.1
2.5
3.5
3.7
4.5
2.2
3.1
3.3
4.0
2.0
2.8
3.0
3.6
1.8
2.5
2.7
3.2
1/1
1/2
1/4
1.0
0.71
0.5
ISO100, m
25
35
42
50
70
85
28
32
35
25
28
32
23
25
28
20
23
25
18
20
22
16
18
20
14
16
18
13
14
16
11
13
14
10
11
13
8.9
10
11
7.9
8.9
9.9
7.1
8.0
8.9
6.3
7.1
7.9
5.6
6.3
7.0
5.0
5.6
6.3
4.5
5.0
5.6
4.0
4.5
5.0
3.5
4.0
4.4
1/8
1/16
0.35
0.25
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