Mamiya 645 AF - Manual (Page 32)

Depth of field
Depth of field (D.O.F) is defined as the zone of sharpness before and behind the plane of
focus. It depends on camera subject/distance, focal length of lens, aperture setting and
distance the lens is focused at.
In addition to visual observation via the depth of field preview button (See page 66.), the
D.O.F can be determined by using the depth of field scale on each lens. f/stop numbers
appear on both the right and left side of the white index mark in the center of the scale.
Simply read the figures which appear above the f/stop numbers on the distance scale of
the lens. (see illustration below)
When the aperture is large
(the subject depth is small)
When the aperture is small
(the subject depth is large)
Infrared Photography
When taking photos using infrared film, the position at which the subject is in focus is
slightly different from during normal photography. This is because the infrared rays
have a longer wavelength and the image converges further back than normal. Use the
procedure described below when taking photos using infrared film.
1. Set the focus as usual. Find the point on the distance scale matching the subject
depth scale's central index.
2. Set the focus mode selector lever to "M" (manual focus mode). Turn the focusing
ring clockwise and set the distance scale to the above infrared index.
*Use a red filter when taking photos using infrared film.
*Be sure to read the infrared film's usage instructions.
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