Nikon SB-30 User Manual

The SB-30’s flash output level can be set manually at M1/1, M1/8, or M1/32. In the Manual mode, 
you must determine the correct exposure by calculation using a combination of the guide number,
shooting distance, and lens aperture.

• If the camera’s exposure mode is set to other than Aperture-Priority Auto (A) or Manual (M), the shutter may

not be released, depending on the cameras in use.

ISO sensitivity

25

50

100

200

400

800

1600

M1/1

8/26

11/36

16/52

22/72

32/105

45/148

64/210

Flash output level

M1/8

2.8/9

4/13

5.6/18

8/26

11/36

16/52

22/72

M1/32

1.4/4.6

2/6.6

2.8/9.2

4/13

5.6/18

8/26

11/36

Flash output level

M1/1

5/16

7.1/23

10/33

14/46

20/66

28/92

40/131

(with wide-flash adapter in place)

M1/8

1.8/5.9

2.5/8.2

3.5/11

5/16

7.1/23

10/33

14/46

M1/32

0.9/3

1.3/4.3

1.8/5.9

2.5/8.2

3.5/11

5/16

7.1/23

• To obtain the correct exposure, use the following equations to determine the aperture and guide number to match the

flash shooting distance.

f/stop (aperture) = Guide number (GN) ÷ Shooting distance (m/ft)
Guide number (GN) =  Aperture x Shooting distance (m/ft)

• For example, when shooting a subject at a distance of 2.5m (8.2 ft), at an ISO sensitivity of 400 and a lens aperture of f/2.8: 

Guide number = 2.8 x 2.5 = 7 (in meters) or 2.8 x 8.2 = approx. 23 (in feet).

Therefore M1/8 is the correct flash output level with the wide-flash adapter in  place.

• Likewise, when shooting a subject at a distance of 4m (13 ft.), at an ISO sensitivity of 400 and M1/1 flash output level

without using the wide-flash adapter:

f/stop = 32 ÷ 4 = 8 (in meters) or 105 ÷ 13 = approx. 8 (in feet). Therefore, f/8 is the correct lens aperture.

SB-30  -E  01.08    2002.12.26    17:23    ページ1 8