Honeywell PENTAX SPOTMATIC IIa Operating Manual page 25

INTERCHANGEABLE LENSES
The Honeywell Pen tax offers many
interchangeable lenses in a wide var¬
iety of focal lengths, all of which are
highly respected by both professional
and amateur photographers for their
fine resolution. The photographic
coverage of the various Takumar
lenses is illustrated on page 24. With
focal length longer than 55mm, the
subject image is seen through the
viewfinder larger than its life size.
FIXED FOCUSING SETTING
Because of the considerable depth of
field of wide-angle lenses, you can use
them as fixed focus lens if the dia¬
phragm and distance scales are set
properly. For your convenience, the
Super-Takumar and SMC Takumar
lenses shown on pages 25 and 26
Regardless of the lens selected for
your Honeywell Pentax, there is
never need for an accessory view¬
finder, ordinarily required for range¬
finder type cameras.
When interchanging lenses, hold the
lens by the distance scale ring. When
attaching a lens, filter, or lenshood,
do not screw it too tightly, as you
may find it difficult to remove.
(marked with *) have a fixed focus
mark. Just align with the index the
orange-colored figures of the dia¬
phragm and distance scales, and the
lens will be in fixed focus from fore¬
ground to infinity. You'll find this ex¬
tremely convenient for fast shooting.
RESOLVING POWER OF TAKUMAR LENSES
Resolving power of all Takumar
lenses is factory-tested by skilled op¬
tical engineers. There are three types
of tests: microscopic aerial test, pro¬
jection test and photographed film
test. Resolving power of a lens shown
by Ipm (lines per mm) varies depend¬
ing upon the method of resolution
test. Takumar lenses have been tested
for resolving power to conform to
Asahi Optical Company standards
which are higher than those set by
JIS (Japan Industrial Standards). All
Takumar lenses bear the seal of the
Japan Camera Inspection Institute
which insures the highest standards
of performance.
When testing your lens perform¬
ance ...
Use a slow-speed fine grain film.
Generally, high speed films are grainy
and are not suitable for resolution
test. Support your camera on a good
tripod. Use a shutter release cable
to prevent camera movement. The
definition of the picture on the nega¬
tive film may decrease if exposure
and developing time are not proper.
Time your exposure and develop¬
ment correctly.
If you do your own developing and
enlarging, see that your enlarger uses
a fine quality enlarger lens. If it is
not of a fine quality, your pictures
can never be sharp no matter what
superb lenses are mounted on your
camera. Usually, the diaphragm of
the enlarger should be closed down
to f/8 or f/ll.
23