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Technical Notes—Optional Accessories
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 8517
D70S 30 36 42 52.5 75 90 127.525.5
35-mm fi lm camera 135 180 200 300 400 500 600105
D70S 202.5 270 300 450 600 750 900157.5
Cal cu lat ing Picture Angle
The size of the area exposed by a 35-mm
camera is 36 × 24 mm. The size of the
area exposed by the D70S, in contrast,
is 23.7 ×15.6 mm. As a result, the picture
angle of photographs taken with the
D70S 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 Angle and Focal Length
A 35-mm cam era has a di ag o nal pic ture angle ap prox i mate ly one-and-a-half
times that of the D70S. When cal cu lat ing the focal length of lenses for the
D70S in 35-mm format, you will therefore need to mul ti ply the focal length
of the lens by 1.5, as shown in the following table:
Picture size (D70S)
Picture size (35-mm format)
Lens
(23.7 mm × 15.6 mm)
Picture diagonal
(36 mm × 24 mm)
Picture angle (35-mm format)
Picture angle (D70S)
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