Nikon D330018-55VR User Manual (en)

298 Technical Notes
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 D3300, in contrast, is 23.5 × 15.6 mm, 
meaning that the angle of view of a 35mm camera is approximately 1.5 
times that of the D3300. The approximate focal length of lenses for the 
D3300 in 35mm format can be calculated by multiplying the focal 
length of the lens by about 1.5.
Picture size (35mm format)
(36 × 24 mm)
Picture diagonal
Picture size (D3300)
(23.5 × 15.6 mm)
Angle of view (35mm format)
Angle of view (D3300)