Nikon Camera Lens - Manual (Page 12)

INFRARED PHOTOGRAPHY
In infrared photography, the plane of focus is slightly behind that of visible light.
Consequently, when you are using infrared film in the camera, you have to
compensate for this difference in focus. With the Zoom-Nikkor 35-70mm f/3.5,
two infrared focusing indices are provided for the focal lengths of 35 and 70mm.
You first focus on your subject in the normal way, then read off the camera-to-
subject distance indicated on the focusing ring. This distance is then set against
the corresponding infrared focusing index for the focal length you are using. For
intermediate focal lengths, you can estimate the corresponding corrective point,
using the engraved lines as a guide.
The scales on page 25 can be used for determining the amount of adjustment
via the dotted infrared compensation line included
In the same manner as described in the "deplh-of-field scale" section, match
the prelocused subject distance fusing the B scale) with the focal length and
aperture scale central indicator line (on the A scale). The distance from the
central indicator line to the dotted compensation line represents the amount of
adjustment required Now, turn the lens' focusing ring counterclockwise until
the prefocused distance is shifted as prescribed on the scales.
FEATURES/SPECIFICATIONS
Focal length: 3570mm
Maximum aperture: f/3 5
Lens construction: 10 elements in 9 groups
Picture angle: 62° '^34°20'
Distance scale: Graduated in meters and feet from 0.7m (2.5 ft) to infinity («»); in
macro focusing mode at 70mm setting, down to 0 35m (1.2 ft)
Zooming control: Independent zooming control ring with rotation of 71°46';
reference marks provided for focal length settings of 35mm, 50mm, and
70mm: zooming is impossible in macro focusing mode
Focusing control: Independent focusing ring with total rotation of 200°55'
Macro focusing function: With the macro focusing button engaged, close-up
photography down to 0 35m (1 2 ft) is possible
Aperture scale: f/3.5~f/22 on both standard and aperture-direct-readout scales,
click-stop at f/4 but not engraved on aperture ring
Diaphragm: Fully automatic
Exposure measurement: Via fuil-aperture method
Mount: Nikon bayonet mount
Attachment size: 62mm (P = 0 75mm)
Dimensions: 66.5mm4 x i05mm (overall), 96.5mm extension from flange
Weight: Approx, 520g