Nikon SB-28 guide numbers at ISO 100 for meters/feet, Do not use the built-inwide flash adapter

%guide numbers (at ISO 100; for meters/feet)

Shutter speed			Zoom-head position
	24mm	28mm	35mm	50mm	70mm	85mm
1/250 sec.	14/46	15/50	17/56	20/65	23/74	24/77
1/500 sec.	10/33	11/36	12/39	14/46	16/52	17/56
1/1000 sec.	7/23	7.5/25	8.5/28	10/33	11/36	12/39
1/2000 sec.	5/16	5.3/17	6/20	7/23	8/26	8.5/28
1/4000 sec.	3.5/11	3.7/12	4.2/14	5/16	5.7/18	6/20

%guide numbers vary with the ISO film speed, shutter speed, and zoom- head position.

Adjustment factors for other ISO film speeds

ISO film speed	25	50	200	400	800
Factor	x 0.5	x 0.71	x 1.4	x 2	x 2.8

•For film speeds other than ISO 100, multiply the guide numbers by the factors shown in the above chart.

For example, for a film speed of ISO 400, with the zoom-head adjusted to 35mm, and a shutter speed of 1/500 sec., the % guide number is 12 x 2 = 24 (m), or 39 x 2 = 78 (ft).

Notes on flash photography in FP High-Speed Flash sync %

• Do not use the built-in wide flash adapter.

When used, M20 or M18, ƒ and % blink on the LCD panel as a warning.

• Detaching the SB-28

When you remove the SB-28 from the F5, F100, F90X/N90s or F90- Series/N90, be sure to cancel FP flash operation. If the flash is removed with the FP setting, % blinks as a warning.

51