Focusing Adjustment; Distance Scale And Depth Of Field Scale - Zenza Bronica ETRS User Manual

17. Focusing Adjustments

18. Distance Scale and Depth of Field Scale

A. The lens is focused on the subject, by rotating the focusing ring in
either direction, while checking the effect on the micro-prism / split-
image rangefinder spot in the center of the focusing screen (standard
type).
B. The central split-image spot splits the image diagonally, with the
upper and lower halves being separated diagonally when the lens is
out of focus. When in focus, however, the two halves will coincide
with the diagonal displacement disappearing.
The micro-prism ring surrounding the central spot can also be used
for checking the sharpness of the focused image, since the image will
glitter when the lens is not focused. The full-area matte surface sur-
rounding the central focusing aids can also be used for checking
image sharpness.
A. Distance scales on the Bronica lenses for the ETRS can be used for
setting the focus on the required distance or finding the distance
actually focused. Simply rotate the focusing ring and set the required
distance opposite the green-colored index, which will adjust the lens
for the required distance.
B. There is an apparent zone of sharpness, both in front and back of
the focused subject, which is known as the depth of field. The depth
of field scale shows the zone of apparent sharpness at any lens open-
ing or distance and can be utilized for quickly and simply ascertain-
ing the depth of field. The depth of field scale is next to the distance
scales and is made up of identical pairs of apertures on both sides of
the green-colored distance index. These identical pairs of apertures
indicate the distance that will be in focus at these lens openings. For
example, if the 75mm lens is focused at a distance of 3m, it can be
seen from the depth of field that the zone will extend from about
1.85 to 8.30 meters (6ft. to 26ft.) when a lens opening of F22 is used.
Please refer to 27. Depth of Field Tables.)
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