Film cameras
Sears Tower No. 18a User manual
User manual for Sears Tower No. 18a. 25 pages in English. Read the original PDF, download or print a copy without registration.
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Document details
- Brand
- Sears
- Model / document
- Sears Tower No. 18a
- Document type
- User manual
- Language
- English
- Pages
- 25
- File size
- 1.7 MB
- Category
- Film cameras
- Document date
- Not specified in catalog
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Page 3 · Read text
NOMENCTATURE
1. Cocking Lever 7. Shutterspeed Scale
2. Shutter Button 8. Aperture Scale
3. Exposure Counter 9. Filmspeed Dial
4. Focusing Lever 10. Meter Marker
5. Exposure Control Ring 11. Meter Scale Guide Lines
(Aperture Adjustment) 12. Meter Needle
(i. Shutterspeed Control 13. Photocell Window
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14. Bzrcklid Czrtch 22. Eyepiece
15. Cartridge Chamber 23. Distance Scale
16. Sprocket 24. Depth of Field Scale
17. Take-up Spool 25. Synchroflash M-X Adjustment
18. Rewind Crank 26. Synchroflash Terminal
19. Sprocket Release Button 27. Self -timer Lever
20. Rewind Indication 28. Zero Point
2I. Viewfinder Window 29. Accessory Clip
30. Strap Eyelets
31. Tripod Socket
32. Focal Plane Mark
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GENERATDESCRIPTION
CAUTION: Read these instructions carefully for a thorough understanding
of the functions of this camera before trying out the actions of the cocking
lever (1), dials, and controls.
CROSS-COUPLEDEXPOSUREIAETER ThC
TOWER 18A has a built-in wide-
(} range exposure meter which permits
an extremely broad range of light-
intensity measurement and exposure
control without shift of scale. Simple,
botherfree operation is possible with
all types of subjects, from bright
snow scenes and beach shots down to
darkly lit interiors where full aperture
and slowest shutterspeed must be used
even with high speed (ASA 100 and
up) film.
To use built-in exposure meter for
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automatic exposure control.
1) First set the filmspeed dial (9) to the ASA rating of the film in use.
Unless this is done, the cross-coupling of the meter indication with the exposure
controls (shutterspeed and aperture dials) will be out of step.
2) Train camera on the subject, making sure that the photocell is not ob-
structed. The meter needle (721 will immediately indicate the brightness of
the subject-matter.
3) When the exposure control ring (5) is adjusted, the aperture scale (8)
shifts in the opposite direction, while the meter marker (10) at the top of the
camera also turns. The meter marker (10) can therefore be easily brought into
alignment with the meter needle (12) through the meter scale guide lines (11).
When this is accomplished, the controls are set for correct expcsure of the film.
4) When alignment cannot be effected without running out of the aperture
scale (8), shifting the shutterspeed control (6) to a lower or higher setting
will facilitate adjustment.
GOGKING.ACIION Holding the camera in both hands, hook right thumb on
cocking lever (1), and push it through an arc of 180" till it comes to a stop.
This action advances the film one frame, cocks the shutter, and shifts the frame
counter up one step. At completion of stroke, the lever will spring back to
# ;a*iige"*"L. "View original page 6Page 7 · Read text
its original position. Cushion this return action with thumb. Once' the camera
is cocked, the cocking lever remains locked until the shutter is released.
COUPTED RANGEFINDER Moving the focusing lever (4) back and forth will
cause the lens-shutter assembly to move in and out. This movement is linked
with the rangefinder system, and the coupled action can be seen in the changes
that occur in the double-image focusing spot at the center of the viewfinder
field. Sight subject through eyepiece (22), and adjust focusing lever (4) so that
overlapping images of the subject in the focusing spot merge. At this point
the subject is in proper focus, and the distance between the camera (focal plane
mark (32) ) and the subject is indicated on the distance scale (23). The focusing
range is from infinity (oo) to 3.5 feet.
Fttil REWIND To return exposed film from take-up spool (17) to safety-
cartridge, press sprocket release button (19) to disengage sprocket (16)
from filmwind mechanism. Erect rewind crank (18) and turn clockwise in
direction of arrow mark. Do not touch sprocket release button (19) or rewind
crank (18) while there still remains unexposed film in the camera. During
rewind action, the red mark on the rewind indication (20) will turn to show
film is being played out of the take-up spool (17) through the freed sprocket
(16). The depressed sprocket release button (i9) will spring out automatically
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ul)on ol)cr:lt iol) of t he cocking lcvcr' ( l )
FILM TOADING
YouI"I-O\VER 10A uses 35-nrillinteter nriniattrre
canlel-ir filnr, nronochronre or color-, in 20 or'36 fr-alne
length. Aln'ays avoid direct sunlight when lolrding
()r' rrnlo:tdirtg culmerit. \Vork in t he sh:rcle, using ()\r'n
bocly if necessary.
I . Prrll upward bzrcklid catch (14) to release ltzrcklicl
*hich will swing open. Pull out rewind crank (181 so
thert its spindle does not protrude into cartridge chamber
( ls) (Fig. 1) .
2. Place safety cartridge containirrg trnexposed film
in cartridge chamber ( l5) , seeing that it fits sn ugly irr
the right direction. Press dowrt rewind crank ( 18) so
that spindle of the rewind crank ellga.qesthe cartridge
:rnd holds it in place. If spindle does not engage cartridgt,
spool properly, turn l-e\l,ilrdcrarrk slightlv until it snapsView original page 8Page 9 · Read text
honte with a click. Next, pull out :tllottt four inches of
film, and fold inward (toward the dull emulsion side)
about a quarter inch of the end (Fig. 2)-
3. Insert folded end in the slit of take-up spool (17),
which can be brought into convellient position by
turning spool in either direction by thumb tip. With
end clf film caught in the slit, turtr sp<ltllso thzrt sprccket
(16) also rotates, atrd wincl at least olte turtr tlf filnr
onto spool, seeing that the perforations on the lower
side of the film engage the sprocket teeth (Fig. 3).
4. Ilolding film taut ancl in positicln, check safety
cartridge, then turn rewind crank ( 18) clockwise, as
indicated, to take up all slack (Fig. 4)-
\ 5. With slack gone, turn take-up spggl (17) slightly
with thumb to see that film and sprocket ( 16) are
properly engaged, and that the rewitrd cratrk (18) turtrs
counterclockwise with the film feeding smoothly out of
the safety cartridge. Close backlid, which u'ill catcfi
when pressed down. If, when clcsing backlid, the
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'':
perforations on both sides of the filmare caught on the sprocket the full number
of exposures may not be available because too much film has been lvound onto
the take-up sprccket.
6 . T u r n i n g t h e m i l l e d f l a n g e a r o u n d t h e h u b o f t h e c c c k i n g l e v e r ( 1 ) , s e t
the exposure counter (3) so that it indicates ,,S', (start).
7. Preferably keeping the lens cover€d, operate cccking lever (1) and shutter
button (2) three times until numeral 1 is indicated by the exposure counter
(3). The camera is now ready for the first picture.
8. when, during cocking action, the film is being taken up properly, the
rewind crank (18) will turn counterclcckwise (against the arrow indication).
If there is no motion, rewind film, taking care that end is not wound into the
safety cartridge ; open backlid, and repeat loading procedure. Do not turn rewind
crank (18) counterclockwise while picture-taking.
' 9. After loading, always turn filmspeed dial (9) to correct ASA setting. ,
CAMERA GRIP
Any comfortable and relaxed manner of holding the camera will do, so long
as the camera can be kept perfectly steady, and the fingers do not obstruct the
viewfinder and rangefinder windowsView original page 10Page 11 · Read text
(iri1r (:lutlcrlr frottr tlre sicles rvitlr lrotlr lurttrls, s() that index or rrriddle fingers of the left harrd catches ()r'r the focusing lever (4), while the right thunrb is hool<ed Iightly on the cccking lever ( 1), ::trd tlre right index finger rests lightly oll the shutter button. 1. For horizontal pictures, bring calltera up t<r eyelevel withcut changing grip. Close left €y€, atrcl sight with right eye thrcugh the eyepiece (22'1. Keep elborvs close to bcdy fc;r tttaximutn steacliness, atrcl hold breath lltoll)elttarily whetr operating sh utte r buttot't (see Cut A). 2. For vertical pictures, there are two basic grips. Methocl otre: Turn callrea over to the left, with left arm held close to the bt:cly for steadirt€ss, attd with left palrtt in firttt ct-rntact with cheek. When f<;cusing in this position, use thunrb and index finger of left hand (Cut R) . Methcd twcr: Turn calnera over to the right, using right thumb and fingers to operate shtttter button and www.orphancameras.comView original page 11
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grip the right side of the canrera. Keep right elbow
close to the body (Cut C).
When using either of these vertical positions, fine
fccusing can be done lnore easily by first focusing
in the horizontal position.
AUTOMATIC EXPOSURECONTROT
l. Check filnrspeed dial (9) to see that it is set at
tlre ASA rating of the filnr in use. @
2. When the cantera is trained on the subject, the
ttreter needle (12) will be deflected away f ronr zero position. By turning the
exposure control ring (5) , the nteter ntarker ( I0) is turned so that it can be
brought into alignnrent with the scale indication of the nteter needle (12) through
the meter scale guide lines ( I 11.
3. If., after the exposure control ring has been turned to the limits of the
apertttre scale, alignntent of the nreter rtrarker ( 10) with the lreter needle scale
indication cannot be effected, further nrovement of the exposure control ring
(5) will cause the shutterspeed scale (7 ) to shift to perrnit nratching of the
nreter nrarker ( l0) with nreter needle deflection.View original page 12Page 13 · Read text
4. Once the meter marker (10) is brought into alignment with the meter needle
(12) through the guide lines (11), the camera is properly adjusted for correct
exposure. Adjustment of the shutterspeed control (6) for change of shutterspeed
will automatically result in a corresponding shift of the aperture setting, and
exposure will always be the same.
5. Consequently, if high fccusing tolerance is desired (see section on depth
of field, below) with small aperture, it is simply a matter of selecting a low
shutterspeed. Conversely, for objects in motion which must be " frozen" in
action, fast shutterspeeds (at reduced focusing tolerance) are used. Shutter-
speed settings must be at the click stops : intermediate positions cannot be used.
The aperture control is continuous, so any position on the scale will give the
corresponding aperture size.
6. If, with the photocell window completely covered, the meter needle (12)
does not indicate zero point, remove screw plug (28) and adjust by moving lever
inside the top casing.
7. The unnumbered steps on the filmspeed dial (9) divide the intervals between
ASA numbers into three equal parts. The two red dots indicate ASA 32 and
ASA 160 respectively.
WHEN PHOTOGRAPHING PEOPTE
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To obtain the proper light value
( brightness) of the subject, the
best way is to lnove up close
enough so that only the light re-
flected by the subject itself excites
t he photocell and light nreter. It
is usually best to exclude the
light fronr the background, sky,
foreground and reflections.
When taking pictures of hunran
subjects, nteasure reflected light
f rom a distance of about f our
or five inches, using the rnean,
-7if desired, of the highlights and
shadows. When nreasrlring brigh -
ness at close range avoid casting a shadow on the subject.
SCENERY
When, in photographing scenery or nraking snapshots, it is difficult to get close
t<-rthe ntain subject-tnatter, point the canrera toward the foreground a few feetView original page 14Page 15 · Read text
away from camera position
in order to avoid overexcita-
tion of the photocell by
strong light from the sky.
(see cut) When photograph-
ing wide vistas or distant
peaks, reduce aperture sett -
ing by one step, or increase
shutterspeed by a step. (see
cut) For example, if the
nreter marker ( 10) is in
alignment with the meter
rreedle (12) when aperture is t I 1I and shutterspeed is at 7 1250, then either
increase shutter-speed to 1/500 or redtrce aperture to f 116.
UNDER REVERSETIGHTING CONDITIONS
l. Silhouette effect can be obtained, when light is coming f ront behind the
subject, if when deternrining the exposure control settings the brightness of the
background, not the subject itself , is measured.
2. To obtain a good reproduction of subject, disregard the background and
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measure the reflected light coming frcm'the subject only by measuring at close range. 3. To obtain a good reproduction of both the subject and the background use the mean of the settings obtained for the subject and background separately. USE OF FIITERS Because filters are effective by virtue of their ability to absorb some of the light they transmit, it is necessary to compensate for this lcss when filters are used. The absorption factor of each filter is indicated by numerals expressing the amount by which expcsure must be increased-e. g. X 2; Xa' & c. With the TOWER 18A compensation is simply effected by adjustment of the filmspeed dial (9). For example, if the film in use is ASA 2C0, and the filter used has a factcr of X2, simply change the setting cf the filmspeed dial (9) to ASA 100: if the factor is x4, change setting to ASA 50. FOCUSING Focusing is done by sighting the subject through the eyepiece (22), and by adjusting the focusing lever (4) while watching the overlapping images in the focusing spot at the center of the viewfinCer field. When the overlapping images appear as a single object, the camera is properly focused on this object. Ac-View original page 16
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cLtr:rte focusing is l)ecessary parrtictrlarly r+,lren photcgr-zrphing at close rar)ge.
Jtrdgnrent of the nrerging of the double image is facilitated by ainring at vertical
lines such as poles, window franres, and other uprights. In por traiture, use
cheek and nose lines, or the sharp outline afforded by eyeglasses.
The bright f ranre outlining the optical field in the viewfinder gives t he
scope of the subject-tnatter registering on the filnr. Since this optical franre is
accurately ct-rupledto the rangefinder and focusing rnechanisnr there is no parallax
€v€n at the closest rang€s.
By conrparing the distance scale (23) and the depth of field scale (24) after
noting the aperture used, it is possible to kncw at a glance the arlrount of
focusing tolerance available.
DEPTH OF FIELD
Depth of field, or focus-
ing tolerance, is the range
along the optical axis of
the camera lens rvithin
which sharp register of
the subject can be ob-
tained. This range de-
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pends on distance and aperture size (f/setting)'
1. The smaller the lens opening, the greater the depth of field or focusing
tolerance.
2. The farther away the subject, the greater the tolerance.
3. The shorter the focal length of the lens, the greater the depth of field.
4. There is more focusing tolerance beyond the subject in focus than in front'
Depth of field depends very much on lens design, and on the degree of sharap-
ness of register (technically, the size of the circle of confusion) required'
The fccusing tolerance (depth of field) of the MAMIYA-SEKOR F 1.9,
f:48mm lens of the TOWER 18A is given in the following table.
With proper awareness of depth of field, it is possible to obtain photographs
with sharp register of subjects at varying distances from the camera.
For example, to obtain a picture of a subject 10 feet (approximately 3 meters)
from the camera in front of a building 40 feet (approximately 12 meters) distant,
both in sharp register, the aperture setting should be at f/8, and the fccus
(distance setting) should be at 15 feet. lf, at the same aperture setting, the
camera is accurately focused on the subject at 10 feet, background objects up
to only 17 f.eet distant will register sharply'
Using this principle, it is possible to dispense with focusing for subjects more
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i
than 13 feet (about 4 meters) distant from the camera by pre-setting the focus
at 30 feet on the distance scale (23) and using aperture settings of f l8 or less
(8, 11, and 16).
UNLOADING FII.M
When the specified number of exposures per roll of film (20 or 36) have been
made, stop picture-taking. Do not attempt to sqeeze in one more frame. Returnt exposed film into safety cartridge for removal from camera.
1. Push sprocket release button (19), it should remain depressed. Erect rewind
crank (18) and turn clockwise, as indicated, to wind film into safety cartridge.
2. When all of the exposed film is rewound into the cartridge, and the end
is detached from the take-up spool (17), this can be felt by a stiffening and
easing of tension. However, if it is desired not to wind the end into the cartridge,
watch the rewind indication (20), and stop rewinding when the sprocket release
button ceases to turn. Open backlid, pull out the rewind crank, and remove
safety cartridge from the camera. The depressed sprocket release button (19)
will automatically teturn to original position when the cocking lever (1) is next
operated.
Caution 1. When more than the specified number of exposures is attempted,
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and in some cases before the full number of frames have been expcsed, the film
may come to an end to cause the cocking lever (1) to jam part way through
its stroke. In such cases never force the lever. Press the sprocket release
button (19) and operate cocking lever while keeping the button depressed. Cock-
ing lever will complete its stroke and return to original position.
Caution 2. If force is applied to the cocking lever (1) when it is held by the
film coming to an end, the film may become detached from the spool in the
safety rnagazine, making it impossible to rewind the exposed film into the maga- *i
zine. In such case, if film is to be saved, open camera in a photographic dark-
room, remove film and replace in safety cartridge or some other lightproof
container.
SHUTTEROPERATION .dFi-
L. All shutter controls-shutterspeed control (6), aperture adjustment (5)
synchroflash M-X adjustment (25), and selftimer lever (27)-may be adjusted
either before or after the cocking lever (1) is operated. It rnakes no difference
whether or not the shutter mechaism is cocked.
2 . T h e s e l f t i m e r c a n b e u s e d o n l y w h e n t h e s y n c h r o f l a s h M . X a d j u s t m e n t ( 2 5 )
is in position " X ". After selftimer lever (27) has been moved, the synchroflash
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M-X adjustnrent remains locked. 3. The cocking lever (1) should never be operated while the shutterspeed scale (7) indicates the space between B and 1. Always set shutterspeed control (6) at click stops in order to avoid damaging the mechanism. 4. The intermediate spaces between the graduations of the shutterspeed dial cannot be used. Only the click-stop positions are valid. 5. The threaded hole at the center of the shutter button (2) is for fitting a cable release. 6. It is generally considered bad practice to keep the shutter cocked for any length of time. However, no harm can result from having the mechanism under tension for a week or two. When the camea is put away for months, it is better to release the shutter. 7. The synchroflash M-X adjustment (25) gives a choice of two positions: " X " and " M ", to permit accurate synchronization of the shutter when it is linked to a flashgun through synchroflash terminal (26). In normal use, when not using synchroflash, the syncroflash adjustment should be kept at position X (no de- layed action of the shutter) 8. When releasing shutter for blank shots, use shutterspeed settings faster than 1/30 second.View original page 22
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SYNCHROFTASH PHOTOGRAPHY
Position " M " The synchroflash adjustment (25) is set at position " M "
when class M flashbulbs (time to peak intensity about 20 milliseconds) are in'
use. Full synchronization is possible at all shutterspeeds including 1/500. Self-
timer cannot be used with adjustment at position " M ".
Position " X " This position is used for full synchronization at all shutter-
speeds in conjunction with a strobo (electoronic) flash, or for shutterspeeds of
1/30 and under with class F flashbulbs (time to peak, about 10 milliseconds).
At this position the selftimer can be used.
In synchroflash photography, the shutterspeed depends upon the permissibf
range of synchronization for the type of flash in use, while the aperture is al-'
termined by the light-reflecting characteristics of the subject, the intensity $f
the flash, and the distance from the flash to subject. Select suitable setti"S
of the shutterspeed and aperture dials on the basis of the instruction comt{S
with the flashbulb or strobo. Do not attempt to use the built-in exposure mefii.
FITTERSFOR TOWER I 8A
For special effects and color correction, filters are essential. Landscape /.
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..&lg&aL:,.. ,,;rd*#*: -..-,-; *dView original page 23From the M. Butkus archive. Original publisher and archive notices are retained.
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