Table of Contents
Advertisement
interlock button on the right of the aperture scale,
then turning the interlocked rings to the desired
aperture and speed combination. When interlocked
the rings move together, increasing or decreasing
the aperture and shutter speed while maintaining
the EV for correct exposure.
Focusing_ and depth-of-fietd
2i,
The focusing ring is the wide ring with a knurled
rubber grip, set closest to the camera body. The dis-
tance scales appear on this ring. The lens is focused
by rotating the focusing ring until the measured
or estimated distance between the subject and the
film plane appears opposite the lens index. The dis-
tance is shown in white for metres, and in orange for
inches/feet.
Objects closer or further away than the selected dis-
tance will appear sharp, within certain limits. The
range of sharp focus, i.e. depth-of-field varies with
the aperture.
The depth-of-field available at any given aperture
setting can be read off the depth-of-field scale on
both sides ofthe central index. The setting in the il-
lustration indicates how to read the depth-of-field
scale at an aperture of f/l l, i.e. approximately from
0.65m (2.3 ft.) to 1.5m (s ft.).
lnfrared photography
26;,,fi,
Infrared (IR) rays (wavelengths longer than 800 nm)
form an image on a plane further away from the lens
than the image plane for visible light. To compen-
sate for this difference you have to align the chosen
1 0
distance against the red IR index instead ofthe nor-
mal lens index. Proceed as follows:
l.Establish the distance to the subject either
by measuring or by focusing on the focusing
screen adapter (see page 13).
2.Note the measured distance or mark the dis-
tance point on the focusing scale opposite the
lens indexline.
3.Adjust the focusing ring until the established
distance point is opposite the red IR index.
Flash sylchronization
tt,
The built-in shutter in the Biogon CFi lens is fully
synchronized. A flash connected to the PC terminal
fires when the shutter is fully open.
When inserting a flash cord into the socket, keep the
lock button pressed in. 0n release, the cord will be
locked into place. To remove, press in the lock but-
ton again.
Electronic flash units can be used at all shutter
speeds (B and I s *l/500 s).
Hyperfocol setting
,.21y9*,31.;,
The very short focal length of the 38 mm Biogon CFi
lens provides both a 90'angle and a large depth-of-
field. This allows successful use of the hyperfocal
distance setting method. It is based on the fact that
the sharply defined area of a photographic image ex-
tends both in front ofand beyond the focusing point
as described in the section covering
'Focusing
and
depth-of-field'. The distances limiting the sharply
defined area are known as the'near limit' and the
'far limit'.
Advertisement
Table of Contents
