Nikon D2X - Manual (Page 256)

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Technical Notes—Optional Accessories
CPU lenses can be iden ti fi ed by the presence of CPU contacts. Type G lenses
are marked with a “G” on the lens barrel, type D lenses with a “D.”
Type G lenses are not equipped with a lens aperture ring. Unlike other CPU
lenses, there is no need to lock the aperture ring at the minimum aperture
setting (maximum f/-number) when using a type G lens.
Picture Angle and Focal Length
The diagonal picture angle of the D2X is less than that of a 35-mm cam-
era. When cal cu lat ing the focal length of the lenses for the D2X in 35-mm
format, mul ti ply the focal length of the lens by about 1.5 (high-speed crop
mode off) or 2 (high-speed crop mode on):
CPU lens Type G lens Type D lens
Cal cu lat ing Picture Angle
The size of the area exposed by a 35-mm cam-
era is 36 × 24 mm. The size of the area exposed
by the D2X, in contrast, is
23.7 × 15.7 mm
(high-speed crop off) or 17.7 × 11.7 mm (high-
speed crop on). As a result, the picture angle
of photographs taken with the D2X differs
from the picture angle for 35-mm cameras,
even when the focal length of the lens and the
distance to the subject are the same.
Picture size
(D2X; high-speed crop off)
Picture size (35-mm format)
Lens
(23.7 mm × 15.7 mm)
Picture size
(D2X; high-speed crop on)
(17.7 mm × 11.1 mm)
Picture diagonal
(36 mm × 24 mm)
Picture angle (35-mm format)
Picture angle
(D2X; high-speed crop off)
Picture angle
(D2X; high-speed crop on)
Picture angle
Approximate focal length (mm) in 35-mm format
(modifi ed for picture angle)
35-mm fi lm camera 20 24 28 35 50 60 85 17
Hi-speed crop: Off 30 36 42 52.5 75 90 127.5 25.5
35-mm fi lm camera 135 180 200 300 400 500 600 105
202.5 270 300 450 600 750 900 157.5
Hi-speed crop: On 40 48 56 70 100 120 170 34
D2X
Hi-speed crop: On 170 360 400 600 800 1000 1200 210
Hi-speed crop: Off
D2X