Rangefioderslviewfinders; Image Sizer - Polaroid 100 Series Repair Manual

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with ftko".tl kngfll.' or
J
1-1 l11i11imdcrs_ Al f/ttt(
j
Ih~ ~olor ~t!in.&).
!I\l' hypcrllH.:al tlisl;lnc,,-" i the
n... ' .. r
Hntit
of the sharp
fi~h.I
when tht!
c.lmer.i
is
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foeusa] 10 INFlNITY\
i~
42 ih:L At f;42
Uh~
bl'll:k and
whit~
st'llingi.
{he hypt'rfocal distan\.'e
tlrops to M fect. The di3gonal fieW of view is 55<>.
-
while tilt' anguJ<lf
field
(;]t
INFINITY) is 36<1 X
4t," .
RANGEFINDERS/VIEWFINDERS
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111t'rc are Ihrt~c
types
of
f.lIlgellnders/v1t'wfindefS
llscd in Polaroid Land aU[om;.atil: pack cameras.
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The first. is a relatively simple image slZ!!r which
frames the subject and provides a scale for
cstj~
mation of distance between e:.lmera and subject.
The second model is a true rangdinderJview~
nnder which focuses by superimposing two
images of
thl;'
subject, Separate windows are
pro~
vided for the focusing and fmming functions. The
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third type js the
Zeiss
Ikon
model which also
focuses
by superimposing
two images.
However.
both the focusing
and
framing images are
viewed
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through
a single
window.
Image Sizer
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The
jma.ge sizer is used on the Model 104, 125.
115. 210,and 315
cameras.
figure 2-7 shows the
internal construction
of
the
image sizer.
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INCIOENT
LIGHT
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GLASS
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MASK
ASSEMeL'I' _""",­
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MASK
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MIRROR
T!J~
_'.;ubJt',:t is
rroj~dl:l1lO
lIn:·
cyt'
km. through
Ill....
Irallsluc-t.'nt
lIi~hmk
mirror.
IA~
tbt"d In
Polaroid c;lInt!ras:.
a
t1khmit" nmror can
bl:
dc­
tinetJ as
an
optil: t1cvio."1:
whkh
rdl",·\:l:o.
an
im.,g~"
impJrting
10
it
a
\:\.:rtOlin
color dlarJct;..>ristit;. while
it allows another
imllg;t' to
pas.,.. through
it
ill ib
natural
",olon•. For
example. Figure
2·7
show~
incident light being rcOt't'lt'd off one side of [h....
dh.::hmit: mirror before
it
rt'Jt;hes the eye. Thl!
inddent light
hikes:
on tht! t"olor of Ih.... mirror
either purple or amber. At the lklnll.! liml.!.lhl.'
scene light passes through the
mirror
10 till.! eye
in its natural colors. In this way. Albada lines
framing
th~
subject
c.m
be contrasted
against
natural
scen~
light.) When
vi~wed.
the subjet't is
outlined by a (r"me of small diamonds.
Th~
diamonds
are the result of !nddent light shining
through the
mask
ass~mbly
{whit:h
forms the
diamonds) lind then reOecting off (he metl'll
mirror and the colored side of (he dichroic
mirror. The
distance
scale. fixed horizontal line.
and
movable
arrow
are
brought to the eye I~ns
in
the
same way.
As the camera is focused. the mask assembly
moves in such a
manner
tha
t
the area el1com~
passed by the
diamonds
is
either
enlarged
or
re~
duced. In coincidence
with
this.
the
arrow
moves
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_ _ _ _ _ SUBJECT
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--===\;!!;===::>-___
IMAGESIZER
L
t -
WINDOW
I
=::r-----Eve LENS
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~ ~FIXEOLINE
=
DISTANCE _ _ _ _
. . . .
~
SCALE . ' • MOVA8t£
S ARROW
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FIG. 2.7 IMAGE SIZER INTERNAL CONFIGURATION
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