Specifications

When you focus on a specific subject, a distance in front of
and behind the subject will appear acceptably sharp in your
picture. This area is called the "DEPTH OF FIELD".
The depth of field can be determined in the following ways:
1. Each lens has a depth of field scale. For example
with a distance of 3m/9.8 ft and using f/16. the area
within the two f/16 marks on the scale (about 2m/6.6 ft ~
8m/26.3 ft) will be in sharp focus. (Fig. 43)
2. When you press the Depth of Field Preview Lever, it
will set the lens diaphragm to the opening previously set
on the F-Stop ring. This enables you to preview visually
the depth of field of the picture. (Fig. 44)
The viewfinder gets darker but the change in focus depth is
still visible.
* Please do not press the Shutter Release Button while pressing the Depth of Field
Preview Lever.
INFRARED PHOTOGRAPHY
The infrared index mark is an index to correct the focusing
point when you use infrared film and red filters. (MIKE: This
does not apply to the color IR film available, the use of color
filters gives nice "false" colors.)
Since infrared light rays have a longer wave-length than visible
light rays, after focusing normally on the subject. you have to
adjust focus by setting that distance against the infrared index
mark.