Nikon D2Xs Manual page 260

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."
CPU lens
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 D2Xs is less than that of a 35-mm cam-
era. When cal cu lat ing the focal length of the lenses for the D2Xs 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):
Picture angle
35-mm fi lm camera
Hi-speed crop: Off
D2Xs
Hi-speed crop: On
35-mm fi lm camera
Hi-speed crop: Off
D2Xs
Hi-speed crop: On
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 D2Xs, 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 D2Xs 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.
246
Type G lens
Approximate focal length (mm) in 35-mm format
(modifi ed for picture angle)
17 20 24
25.5 30 36
34 40 48
105 135 180
157.5 202.5 270
210 170 360
Type D lens
28 35 50
42 52.5 75
56 70 100
200 300 400
300 450 600
400 600 800
Lens
Picture angle (35-mm format)
Picture angle
(D2Xs; high-speed crop off)
Picture angle
(D2Xs; high-speed crop on)
60 85
90 127.5
120 170
500 600
750 900
1000 1200
Picture size (35-mm format)
(36 mm × 24 mm)
Picture diagonal
Picture size
(D2Xs; high-speed crop off)
(23.7 mm × 15.7 mm)
Picture size
(D2Xs; high-speed crop on)
(17.7 mm × 11.7 mm)