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2. Lens_Holder {Fig. #61}
The lens holder consists of the lens holder barrel
{9), the focus knob (16) and the lens friction
drive pinion, the upper and lower shoe pins {12}
and springr {14} and {15}.
3. Adiustments
". l-.tln Shoe Pressure
The pressure of the film shoe against the film
is maintained by the tension springs {14 & 15}
located behind the shoe pins {12}. Excessive
film shoe tension will cause unnecessary film
wear, inzufficient tension can cause an un-
st€ady picture, excessive film gate noise and
uneven or erratic focus. To test the film shoe
pressur€ retract the cam claw, insert a strip of
film in the gate and slos€ the gate. Attach a
gfam scal; to the end ofthe fitm at the top- A
gentle steady pull should produce about 90 to
ll0 grarm of pull, indicating the corrcct film
shoe pressure. To adjust the presrure, stretch,
shorten or replace the shoe springs,
NOIE:
The upper spring is shorter than the
lower spring. The extra tensien af the lower
spring is designed to overcome the film move-
ment caused by the claw action at the lower end
of the film shoe- lt is important the shoe pins
move freely in the lens holder. lf noq clean
away any dirt or grease restricting its free
movement. Do not lubricate.
b- Film Shoe Position
WEenlE gat€ is closed the film shoe should
line up along the edge of the outer guide rail
and seat flat against the aprrture plate. To
adjust the position of the film shoe, loosen
the retaining plate scrsws [11], close the film
gate and insert one film thickness between
the outer rail and the film shoe. {Fig. #6?}
Reposition the retaining plate to obtain
moderate tensios on the film and secure the
rctaining plate screws (11|. Open and close
the gate to be sure the film shoe seats com-
pf etefy.
Fic.see
c. Uneven Fscu;
Uneven focus occurs whenever the image on
the film is not flat and perpendicular to the
optical path. To adiust the axis of the lens to
the aperture plate, set the proiector to exact
right angles to the screen. Without a film in
the gate, project an image of light on a screen
at least 3'or lm wide. Focusthgedgesof the
image. lf both sides ar-e not focused equally,
adiust the lens holder index screv,, and lock
nut {19 A 2A} to achieve optimum equal
focus.
NOTE: Fast lenses such as the standard fi 1 .2
50mm {2"}
require more precise
adjustments than slower lenses.
d, Lens Holder Hinge Adiustment
The lens holder provides for autamatic closing
of the No. 1 film shoe when manually thread-
1 S
F I L M
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