Internal Flash Guide Numbers (Feet) - Nikon D300 Complete Manual

2. Activate the flash by popping it up (press the Flash
Release button).
3. Set the camera to Single Servo AF; flash only operates
when the camera achieves focus; this step isn't
technically required, but I like to tell people to use it
as a reminder that focus has to be achieved for flash to
operate.
4. Focus on your subject by pressing lightly on the
shutter release. Note the distance on the scale on the
lens.
5.
Aperture = GN / Distance
correct aperture. (Determine the GN by looking at the
tables, below).
6. Set the D300 to the exposure mode you wish to use,
and set your aperture and shutter speed, as usual. Just
make sure that the aperture you set matches the one
you just calculated in Step 5!

Internal Flash Guide Numbers (Feet)

Output Level
Full Power
1/2 Power
1/4 Power
1/8 Power
1/16 Power
1/32 Power
1/64 Power
1/128 Power
Thom Hogan's Complete Guide to the Nikon D300
> key to select the flash power to be used.
. Work the calculation and set the
ISO 100 200
42 59
30 42
21 30
15 21
11 15
7.8 11
5.6 7.8
4 5.6
400 800
82 115
59 82
42 59
30 42
21 30
14 21
11 14
7.8 11
V1.02
1600 3200
161 225
115 161
83 115
59 83
42 59
30 42
21 30
14 21
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