Nikon D500 User Manual page 351

A
Calculating Angle of View
The size of the area exposed by a 35mm camera is 36 × 24 mm. The
size of the area exposed by the D500 when DX (24×16) is selected for
Choose image area in the photo shooting menu, in contrast, is
23.5 × 15.7 mm, meaning that the angle of view of a 35mm camera is
approximately 1.5 times that of the D500 (when 1.3× (18×12) is
selected, the size of the area exposed decreases, further reducing the
angle of view by about 1.3×).
Lens
35 mm format picture size (36 × 24 mm)
Picture size when DX (24×16) is selected for
Choose image area (23.5 × 15.7 mm)
Picture size when 1.3× (18×12) is selected for
Choose image area (18.0 × 12.0 mm)
Angle of view when DX (24×16) is selected for
Angle of view when 1.3× (18×12) is selected for
Picture diagonal
35 mm format angle of view
Choose image area
Choose image area
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