Nikon D70 - Manual (Page 195)

185
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 85 17
D70 30 36 42 52.5 75 90 127.5 25.5
35-mm fi lm camera 135 180 200 300 400 500 600 105
D70 202.5 270 300 450 600 750 900 157.5
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 D70, in contrast,
is 23.7 ×15.6 mm. As a result, the picture
angle of photographs taken with the D70
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 D70. When cal cu lat ing the focal length of lenses for the
D70 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 (D70)
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 (D70)