Nikon D40X - Manual (Page 111)

Technical Notes/Optional Accessories 99
Optional Flash Units (Speedlights)
The accessory shoe allows SB-series Speedlights, including the SB-
400, 800, 600, 80DX, 28DX, 28, 27, 23, 22S, and 29S to be mounted
directly on the camera without a sync cable. It is equipped with a
safety lock for Speedlights with a locking pin, such as the SB-800
and SB-600. Before attaching an optional flash unit, remove the
accessory shoe cover. The built-in flash will not fire when an
optional Speedlight is attached.
When used with compatible flash units such as the optional SB-400, SB-800, and SB-600
Speedlights or SB-R200 wireless remote Speedlight, the D40x supports the advanced Nikon
Creative Lighting System (CLS), including i-TTL flash control and Flash Color Information
Communication. See the Speedlight manual for details.
SB-400, SB-800, and SB-600 Speedlights
These high-performance Speedlights have Guide Numbers of 21/69 (18-mm zoom cover-
age), 38/125 (35-mm zoom head position), and 30/98 (35-mm zoom head position) respec-
tively (m/ft, ISO 100, 20°C
/68 °F). The flash head can be rotated through 90° above the
horizontal for bounce-flash or close-up photography. The SB-800 and SB-600 can also be
rotated 180° left and 90° right, and the SB-800 can be rotated 7° below the horizontal. The
SB-800 and SB-600 support auto power zoom (24–105mm and 24–85mm, respectively),
ensuring that the illuminating angle is adjusted in accord with lens focal length and have
both a built-in wide panel that can be used for an angle of 14mm (the SB-800 also supports
17mm) and an illuminator that can be used when adjusting settings in the dark.
SB-R200 Wireless Remote Speedlight
This high-performance wireless remote Speedlight has a Guide Number of 14/49 (m/ft, ISO
200, 20°C
/68 °F; GN at ISO 100 is 10/32). Although it can not be mounted directly on the
accessory shoe, it can be controlled using an optional SB-800 Speedlight or SU-800 wireless
Speedlight commander. The SB-R200 can be hand-held, placed on an AS-20 Speedlight
stand, or mounted on the camera lens using the SX-1 attachment for remote control and
close-up i-TTL photography.
SU-800 Wireless Speedlight Commander
The SU-800 can be used as a commander for remote SB-800, 600, or R200 flash units. The
SU-800 itself is not equipped with a flash.
Guide Number
To calculate the range of the flash at full power, divide the Guide Number by the aperture. For exam-
ple, at ISO 100 the SB-400 has a Guide Number of 21m or 69ft.; its range at an aperture of f/5.6 is
21÷5.6 or about 3.7 meters (or in feet, 69÷5.6=12ft. 4in.). For each twofold increase in ISO sensitivity,
multiply the Guide Number by the square root of two (approximately 1.4).