Kodak DCS600 Guide Numbers for Determining the Correct Aperture, Calculating the Correct Aperture

Guide Numbers for Determining the Correct Aperture

Guide numbers help you determine a correct exposure or proper aperture (f/stop) when

using the SB-28D in the Manual M or Repeating Flash mode.

The guide number represents the amount of light at ISO 200 for meters/feet (m/ft) generated by the flash. With the SB-28D, you can calculate a correct aperture or desired flash shooting distance by using the following equations and the guide number table.

Calculating the Correct Aperture

f/stop (aperture) =	Guide number
	Flash shooting distance (m/ft)

Calculating the Shooting Distance

flash shooting distance (m/ft) =	Guide number
	f/stop (aperture)

Guide Number Table

Guide Numbers in meters/feet at ISO 200 in Manual and Repeating Flash modes.

Flash				Zoom-head position
Output
	18mm	20mm	24mm		28mm	35mm	50mm	70mm	85mm
Level
1/1 (full)	25/84	28/93	42/139		45/148	51/167	59/195	68/223	71/232
1/2	18/59	20/66	30/98		32/105	36/118	42/138	48/157	50/164
1/4	12.7/42	14/46	21/69		22.5/74	25.5/84	30/98	34/112	36/118
1/8	9/30	10/33	15/49		16/53	18/59	21/69	24/79	25/82
1/16	6.4/21	7/23	10.5/35		11.3/37	12.7/42	15/49	17/56	18/59
1/32	4.5/15	5/16	7.5/25		8/26	9/30	10.5/35	12/39	12.7/42
1/64	3.2/10	3.5/11	5.3/17		5.7/19	6.4/21	7.5/25	8.5/28	9/30

11

Flash

11-17