Nikon D1 Manual page 124

Identifying D-Type Nikkor Lenses with a Built-in CPU
D-Type Nikkor lenses with a built-in CPU can be identified by the CPU contacts
(A) and the "D" mark on the lens (B).
A
Lens Focal Length and Picture Angle
The size of the area exposed with a 35mm camera is 24
of the D1, however, it is 15.6
photographs taken with the D1 will differ from the picture angle for 35mm
cameras, even when the focal length of the lens and the distance to the subject
are the same.
The diagonal picture angle of a 35mm camera is roughly 1.5 times that of the
D1. Consequently when a lens of a given focal length is attached to the D1,
the corresponding focal length in 35mm format at the D1's picture angle can
be calculated by multiplying the focal length of the lens by 1.5. The following
chart shows some examples:
Picture
angle
35mm camera 17
D1 25.5
Picture
angle
35mm camera 105
D1 157.5 202.5
Tip
"Picture angle"
Picture angle determines how much of the subject appears in the final photograph.
Technical Notes: Compatible Lenses
B
23.7mm. Consequently, the picture angle of
Focal length (mm) in 35mm format
modified for picture angle
20 24 28 35
30 36 42 52.5
Focal length (mm) in 35mm format
modified for picture angle
135 180 200 300
270 300 450
36mm. In the case
50 60 85
75 90 127.5
400 500 600
600 750 900
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