Nikon D70 manual Picture Angle and Focal Length, 185, Calculating Picture Angle

Picture Angle and Focal Length

A 35-mm camera has a diagonal picture angle approximately one-and-a-half times that of the D70. When calculating the focal length of lenses for the D70 in 35-mm format, you will therefore need to multiply the focal length of the lens by 1.5, as shown in the following table:

			Approximate focal length (mm) in 35-mm format
	Picture angle			(modified for picture angle)
35-mm film camera		17	20	24	28	35	50	60	85
	D70	25.5	30	36	42	52.5	75	90	127.5
35-mm film camera		105	135	180	200	300	400	500	600
	D70	157.5	202.5	270	300	450	600	750	900

Technical Notes—Optional Accessories

Calculating 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,	Lens
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 size (35-mm format) (36 mm ⋅ 24 mm)

Picture diagonal

Picture size (D70) (23.7 mm ⋅ 15.6 mm)

Picture angle (35-mm format)

Picture angle (D70)

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