Nikon AI-S Micro-NIKKOR 105mm f-2.8 - Manual (Page 16)

until the image appears sharp on the focusing screen.
• The tightening screw is indexed “4” for one-fourth.
Depth of field
Depth of field refers to the zone of acceptable focus
in front of and behind the area of sharpest focus in
your shot. At high reproduction ratios, depth of
field is extremely shallow; it’s best, therefore, to
preview before actual shooting. One way to do this is
to press the depth-of-field button on your camera
and the lens will close to the preselected aperture,
showing you how much background and foreground
is in focus. Another way is to read the color-coded
indicators inscribed on the lens barrel. The pairs of
colored lines on either side of the distance index line
correspond to the f/numbers of the same color on
the aperture scale. At close distances, however, so
little is in focus that it may be more useful to check
the depth-of-field tables on pages 32 and 33.