Nikon SB-26 Instruction Manual - Page 60

Guide Number - To Calculate a Proper Aperture The "guide number" helps you determine a correct aperture or f/stop value for using the SB-26's Manual Flash and Repeating-Flash mode. (See "Guide number" chart, page 143.) Use the following equation for your calculations, and check the following chart for guide numbers at various film speeds. [f/stop] = [guide number] [flash-to-subject distance] For example, when shooting a subject located 9 m (approx. 30 ft.) away at 1/1 (full) light output in i (Manual Flash) mode, with a zoom-head position of 35mm and a film speed of ISO 100, you will obtain a guide number of 36 (or 118) from the same chart on page 143. If measuring in meters; [f/stop] =396 = 4 Or, if measuring in feet; [f/stop] = 118 30 = 3.93 ≈ 4 You should then choose f/4 as the proper aperture. For films other than ISO 100, multiply the above figures by the factors shown in the following chart: Adjustment factors for other ISO film speeds ISO film speed 25 50 100 200 400 500 1600 Factor x 0.5 x 0.71 x 1 x 1.4 x 2 x 2.8 x 4 APPLICABLE NIKON SLR MODELS F5 E F-601M/N6000 E FE2 F90X/N90s E F50-Series/N50 E FG F90-Series/N90 E F-401x/N5005 E Nikonos V F70-Series/N70 E F-501/N2020 E F3-Series F4-Series E F-301/N2000 E F2-Series F-801/N8008 E F-401/N4004 E FM2 F-801s/N8008s E F-401s/N4004s E FG-20 F-601/N6006 E FA E 118 If the film speed in the above example was ISO 400 rather than ISO 100: E [f/stop] =396 x 2 = 4 x 2 = 8 E Or, if measuring in feet; E [f/stop] = 118 30 x 2 = 3.93 x 2 = 7.86 ≈ 8 E You should then choose f/8 as the proper aperture. E E E Diffusing Light - To Soften Harsh Shadows With a subject in front of a wall, a direct flash causes harsh and unattractive shadows. By bouncing the light off the ceiling or walls, or by diffusing the light with card(s) or paper, you can soften harsh shadows and create attractive portraits. The SB-26 comes with a built-in diffuser. You can use it alone or with a combination of other reflecting surfaces for advanced application. There are a few ways to diffuse light: 1. Bounce light off a broad reflective surface such as the ceiling. 2. Use both the ceiling and the built-in diffuser card to create a catchlight for subject's eyes. 3. Use a diffuser between the flash and the subject. Chapter 4 1. Light can be bounced off the ceiling. 2. Natural-appearing light with a pleasing catchlight in the eyes. APPLICABLE NIKON SLR MODELS F5 E F-601M/N6000 E FE2 E F90X/N90s E F50-Series/N50 E FG E F90-Series/N90 E F-401x/N5005 E Nikonos V E F70-Series/N70 E F-501/N2020 E F3-Series E F4-Series E F-301/N2000 E F2-Series E F-801/N8008 E F-401/N4004 E FM2 E F-801s/N8008s E F-401s/N4004s E FG-20 E F-601/N6006 E FA E 3. Use some translucent material between the flash unit and subject. 119