Technical Notes—Optional Accessories

CPU lenses can be identified 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 lens

Type D 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 calculating the focal length of the lenses for the D2Xs in 35-mm format, multiply the focal length of the lens by about 1.5 (high-speed crop mode off) or 2 (high-speed crop mode on):

 

 

 

Approximate focal length (mm) in 35-mm format

 

 

Picture angle

 

 

(modified for picture angle)

 

 

 

 

35-mm film camera

17

20

24

28

35

50

60

85

 

D2Xs

Hi-speed crop: Off

25.5

30

36

42

52.5

75

90

127.5

Hi-speed crop: On

34

40

48

56

70

100

120

170

 

 

 

 

 

 

 

 

 

 

 

 

35-mm film camera

105

135

180

200

300

400

500

600

D2Xs

Hi-speed crop: Off

157.5

202.5

270

300

450

600

750

900

Hi-speed crop: On

210

170

360

400

600

800

1000

1200

Calculating 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.

Lens

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)

Picture angle (35-mm format)

Picture angle

(D2Xs; high-speed crop off)

Picture angle

(D2Xs; high-speed crop on)

246

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Image 260
Nikon D2Xs manual Picture Angle and Focal Length, 246, Calculating Picture Angle