Nikon VAA109EA User 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 B Lens Focal Length and Picture Angle The size of the area exposed with a 35mm camera is 24 × 36mm. In the case of the D1, however, it is 15.6 × 23.7mm. Consequently, the picture angle of 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 D1 17 25.5 Focal length (mm) in 35mm format modified for picture angle 20 24 28 35 50 60 30 36 42 52.5 75 90 85 127.5 Picture angle Focal length (mm) in 35mm format modified for picture angle 35mm camera 105 135 180 200 300 400 500 600 D1 157.5 202.5 270 300 450 600 750 900 Tip "Picture angle" Picture angle determines how much of the subject appears in the final photograph. Technical Notes: Compatible Lenses 111