PRIMO-JR User manual

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TABLE OF CONTENTS

Page


I. GENERAL DESCRIPTION AND MAJOR FEATURES  2- 3


II. SPECIAL NOTES ON OPERATION AND CARE   4--- 5


III. PRINCIPAL CAMERA PARTS  6- 7


IV. LOADING, ADVANCING AND UNLOADING FILM  8-14


V. EXPOSING THE FILM  14--20


VI. VIEWING AND FOCUSING  21-24

VII. DETERMINING THE DEPTH-OF-FIELD  24-28


VIII. FLASH SYNCHRONIZATION ...   .  28-29

SHUTTER SPEED AND F-STOP COMBINATION
AT VARIOUS LIGHT VALUE INDEXES  19
 DEPTH-OF-FIELD TABLE FOR PRIMO-JR


REFLEX CAMERA  26
CHART SHOWING RELATIONSHIP OF SYNCHRO SETTING,


FLASH BULB TYPE AND SHUTTER SPEED   29


LIGHT VALUE INDEX EXPOSURE CHART .. 30





                    I. GENERAL DESCRIPTION AND MAJOR FEATURES


The PRIMO-JR is a twin lens reflex type camera taking 12 exposures
of 4 cm x 4 cm size on No. 127 film. It has all the advantageous
features of the twin reflex camera such as ease of handling and
sharpness of focus, plus the added advantages of compact size and
light weight of the 35 mm camera. The use of the 127 size film
produces slides which give one and a half times larger film surface
than 35 mm slides for use on projectors designed for 35 mm slides.
Additionally, contact prints made from No. 127 films are large
enough to permit satisfactory enjoyment even without enlarging.

The taking lens is a TOPCOR f/2.8 60 mm 4-element lens of high
resolving power. The remarkable sharpness of this world-famous lens
can be readily appreciated when slides taken with the PRIMO-JR are
projected on the screen or when enlargement prints are closely
inspected for sharpness of focus. A TOKO f/2.8 60 mm 3-element
viewing lens assures bright reflection. The Fresnel lens installed
beneath the ground glass screen increases the brightness of the
reflected image by 2.5 times at the center and almost 10 times at the
four corners. In addition, there is a 2.5 power magnifying glass to aid
in critical "hair-line" focusing. Parallax compensating lines are etched
on the ground glass and close-ups to about 24 inches can be made
without the use of close-up adapters and parallax compensators.





The SEIKOSHA shutter is calibrated for Light Value System and
has speeds of Bulb, 1, 1/2, 1/5, 1/10, 1/25, 1/50, 1/100, 1/250, 1/500
seconds. Flash synchronization settings are M, F, and X. The Light
Value Scale intervals, except for 1/500, are in alignment so that the
changes in shutter speeds and F-stops are coupled automatically.

The film is transported by an one-action pendulum swing of the
crank which makes rapid sequence photography possible. The
shutter is set simultaneously with the winding of the film. Except for
the initial setting at "1", film exposure counting is also automatic
and the exposure counter advances to ZERO mark ® after the last
exposure is made and the film is completely wound en the Take-up
Spool.

II. SPECIAL NOTES ON OPERATION AND CARE


This camera is a precision instrument. So please read the following
notes carefully to insure long life and satisfactory operation of
your camera.

1. Do not move the Exposure Counter Activating Button (15)
when the camera is empty.

2. In case the Shutter Release Button (10) or the Film Winding
Crank (13) becomes jammed on an empty camera, open the Back,
remove the Film Take-up Spool and turn the gear with your finger
tips until the Film Exposure Counter advances to ZERO mark .

3. To avoid damage to the shutter mechanism, do not re-set the
shutter from the 1/500 speed AFTER it has been wound.

4. Do not leave the camera with the shutter wound for any period
of time because this will weaken the delicate shutter springs.

5. To preserve the life of the shutter, leave the Synchro Setting
Lever at "X" position when the camera is not used for flash
photography.

6. Take extreme care in cleaning the lenses by using only very soft
lens brush or clean soft chamois or soft bleached gauze daubed
with a little alcohol or ether.

7. After using the camera at the seashore or in extremely damp
weather, wipe it thoroughly with dry soft cloth.

8. When storing the camera for a long period of time, keep it in a
plastic or vinyl bag with some moisture-absorbent, like silica gel.

9. If any part fails to work smoothly, do not force it but read carefully
the relevant section of this operating instructions once more.

III. PRINCIPAL CAMERA PARTS


 1. Focusing Hood

 2. Eye-level View-finder Frame Plate

                                                     20. Eye-level View-finder Release Button 3. Shutter Speed and F-stop Indicator Window

                                                     21. Film Take-up Spool Pull-out Knob 4. Bayonet Mount for Accessory Attachment

                                                     22. Red Window Cover 5. Viewing Lens

                                                     23. Red Window24. Focusing Knob
 6. Combined F-stop and Light Value Setting Lever
                                                     25. Film Speed Indicator Disc
 7. Light Value Scale
                                                     26. Distance Scale
 8. Taking Lens
                                                     27. Depth-of-Field Scale
 9. Synchro-terminal
                                                     28. Neck Strap Eyelet
 10. Shutter Release Button
                                                     29. Tripod Socket
 11. M.F.X. Setting Lever
                                                     30. Back Cover Locking Disc
 12. Shutter Speed Setting Lever
                                                     31. Back Cover
13. Film Winding Crank
                                                     32. Film Take-up Shaft Key
 14. Exposure Counter Window
                                                     33. Anti-reflection Baffles
 15. Exposure Counter Activating Button
                                                     34. Film Guides
 16. Exposure Counter Activating Button Safety
Lock                                                     35. Film Spool Holder

 17. Magnifying Glass                                                     36. Film Feed Trough Plate

 18. Eye-level View-finder Rear Plate                                                     37. Film Pressure Plate

 19. Eye-level View-finder Rear Sight

IV. LOADING, ADVANCING AND UNLOADING
                       FILM


                                  A. To Open Camera

                                          (1) Unlock Back Cover (31) by turning the Back Cover
                                 Locking Disc (30) as far as it will go towards "O" (Open)

                                         (2) Lift up Locking Clip and swing Back Cover (31) to full
                                 open position.



                      B. To Insert Film


                                       (1) Pull Film Take-up Spool Pull-out Knob (21 all the way out
                               and give it a quarter turn to lock in position.


                                       (2) Insert slotted end of the film Take-up Spool into Film
                                Take-up Shaft Key (32). (Note : This operation can be
                                          facilitated by first turning the Film Winding Crank (13) until
                                     the Key is in horizontal position.)





(3) Release Film Take-up Pull-out Knob (21) back into place.


(4) Slowly turn Film Winding Crank (13) to make certain that
the Take-up Spool is revolving properly. Stop when the
longer slit on the spool faces up.




(5) Pull back Film Feed Trough Plate (36) against spring
tension, then release and lock Spool Holder (35) into
stationary position by catching lug in hole.

(6) Install new roll of No. 127 film into position on the Film
Spool Holder (35) with the printed side of the backing paper
facing out and the open end pointing directly towards the
Take-up Spool.

(7) Break and remove seal.


(8) Pull out about 4 inches of the backing paper and insert the
tapered end as far as it will go into the slot of the Take-up
Spool.





                                  (Note : Make sure that the film is centered evenly on the
                                      take-up spool; otherwise it may climb on the end of the
                                     spool after the camera is closed and cause tearing of the
                                        paper).

                                          (9) Slowly turn the Film Winding Crank

                                      (10) Release the Film Spool Holder (35) to free position by
                                       pulling back on the Film Feed Trough Plate (36).

                                      (11) two or three full revolutions and make certain that the
                                      film is being correctly transported.

C. To Close Camera

                                       1) Close Back Cover (31) and snap Locking Clip back into
                                         position.
                                   (Note : Make certain that the Locking Clip has engaged the
                                        short stud on the Camera Body.)


                                         (2) Lock Back Cover (31) firmly by turning back Cover
                                 Locking Disc (30) all the way towards "C" (Close).





D. To Advance Film


(1) Open Red Window (23) on the back of the Camera.


(2) Slowly turn Film Winding Crank (13) until the No. 1
mark on the film backing paper appears in the center of Red
Window (23).





(3) Press down on Exposure Counter Activating Button
Safety Lock (16) and shift Exposure Counter Activating
Button (15) to the left.




The shutter is now automatically wound and the camera is
ready for the first exposure. "Note : A click will be heard and
numeral "1" will appear in Exposure Counter Window (14).)

(4) After making the first exposure, raise Film Winding
Crank (13) into position and swing down 180`. Next swing up
towards starting position until it comes to a stop ; fold back
into inactive position. Numeral "2" will automatically appear
in Exposure Counter Window (14). The shutter is
automatically set for the second exposure.

5) After the 12th exposure is completed, the !•: mark will
                                      automatically re-appear in Exposure Counter Window (14)
                                 and Film Winding Crank (13) will revolve freely.



                               Keep on revolving until there is no drag. This indicates that
                                       the film has been fully wound on the Take-up Spool.





                                      Carefully open the Camera and unload film by pulling out
                                  Film Take-up Spool Pull-out Knob (21).

                                   Fold back end of film backing paper and seal. Replace in
                                         original container.





FILM SPEED INDICATOR



Since the faster the speed of the film used, the less the
exposure required, it is convenient to remember the type of
film loaded in the camera. The Film Speed Indicator (25) is
provided for as a reminder and consists of a stationary dial
and movable pointer which lines up with the appropriate
ASA number for both Color and Black-and-White films. To
operate the Indicator, press down and turn the milled button
in the center of Focusing Knob (24).

SPECIAL PRECAUTION

1. The film take-up gear drive is designed to allow free full
revolutions of Film Winding Crank (13) only when the
camera is empty and the free position is indicated by the "0"
mark in Exposure Counter Window (14). In case Exposure
Counter Activating Button (15) is accidentally moved, the
film winding mechanism may jam and it will not be possible
to turn Film Winding Crank (13).

In case this happens, (1) Open the camera, (2) Remove the
spool from the take-up chamber, (3) Revolve the geared
wheel until the free position mark "O" re-appears and (4)
Press Shutter Release Button (10).





2. The same operation as detailed above has to be followed in case the film is taken out of
the camera before 12 exposures are completed.

3. After the camera has been loaded, operate Film Winding Crank (13) with one continuous
"down-and-up" pendulum swing. In other words, avoid transporting the film with short
jerky motions.


V. EXPOSING THE FILM


A photographic image is made by exposing the film to a controlled amount of light
which enters the camera through the lens. The amount of light admitted into the camera
is controlled by (1) the length of time the shutter remains open and (2) the size of lens
opening or "F-stop" as it is sometimes called. Since the amount of light required to
reproduce the image on the unexposed film is fixed, the shutter speed and F-stop are
interdependent. Stating this in other words, a small lens opening (represented by a high
F-stop number) will require longer light admission time, i.e. slow shutter speed.
Conversely, a fast shutter speed will require a larger lens opening.

The shutter speed is indicated by red numerals appearing in
Shutter Speed and F-stop Indicator Window (3) and except
for "B" and "1" are fractions of a second; for example, "2"
equals 1/2 of one second, "25" equals 1 /25th of one second
and "500" equals 1/500th of one second. "B" stands for
"bulb" which means that the shutter will remain in the open
position as long as Shutter Release Button (10) is kept
pressed in.

The shutter speed is set by moving Shutter Speed Setting
Lever (12) to the required position. The lens opening is
indicated in black numerals and represents the following F-
stop values 2.8, 4, 5.6, 8, 11, 16 and 22.


Most light is admitted on the lowest value of the scale, i. e.
f/2.8 and there is approximately a 50 % decrease for each
successive higher F-stop after f/2.8 with the least amount of
light passing through the lens at f/22.


 In photographing a picture-subject, there are three factors
which must be taken into account; namely, the brightness of
the object to be photographed, whether it is in motion, and
the speed or sensitivity of the film used. To obtain a good
photograph it is important to ascertain the proper
combination of shutter speed and lens opening before
exposing the film. This is done either by setting the shutter
speed and lens opening separately or by setting the light
value index only.





Determining Proper Exposure by the Light Value System:


It has been said in the foregoing that shutter speed and lens opening are interdependent.
Since the lens opening determines, in part, the near and far limits of sharp focus and
since the shutter speed must take into account the rate of speed of a moving object, the
problem of obtaining the proper F-stop and shutter speed combination has heretofore
been a source of perplexity to most beginners.

A light value index simplifies this by representing the correct relationship between the
shutter speed and lens opening with one number or index. It is determined with an
exposure meter with a light value scale or by following the exposure chart provided for
in the final page of this operating instructions. To obtain the correct exposure, this index
is transferred to the corresponding index on Light Value Scale (7) of the camera.
Movement of Shutter Speed Setting Lever (12) will automatically change the lens
opening within the limits of the same light value index and since the two are coupled,
various combinations of proper shutter speed and lens opening are obtained for correct
exposure under various conditions.





To illustrate this by a concrete example: Suppose
we are using an ASA 100 film and photographing
a street scene at mid-day in spring for which the
Light Value Index is "13". This means that shutter
speed lens opening combination should be 1/50-
f/12.8

Move Combined F-stop and Light Value Setting
Lever (6) to "13" on Light Value Scale (7). In case
this Light Value Index should fall outside the
range of travel of Combined F-stop and Light
Value Setting Lever (6), move Shutter Speed
Setting Lever (12) until the required Index "13"
comes within the range of travel of Combined F-
stop and Light Value Setting Lever (6).

If the picture-subject is in motion, the shutter
speed can be changed to 1/100 sec. by moving
Shutter Speed Setting Lever (12). Setting the
shutter to this new speed will automatically set the
lens opening to f/9.1 resulting in a new
combination of 1/100 - f/9.1 to give the same
exposure as the original 1/50 - f/12.8 combination.

On the other hand, let us suppose that a greater
depth-of-field is desired and the lens opening of
f/11 is called for. Move Shutter Speed Setting
Lever (12) until the black numeral "11" appears in
Shutter Speed and F-stop Indicator Window (3)
indicating that the F-stop value is f/11. The shutter
speed will automatically shift to the slower speed
of 1/50 sec. to give us the same exposure as the
two foregoing combinations.

The table on page 19 shows in chart form the inter-relationship between shutter speeds and F-stops
for the various light value indexes.

NOTE:


1. From the Chart on page 19, it will be observed that for any given shutter speed the range within
which it is coupled automatically with the F-stop is restricted; for example, for 1/50 sec. the shutter
speed and the lens opening are automatically coupled for Light Value Indexes between "9" and "14"
only. Therefore, if the light value reading on the exposure meter happens to be "5", it will be
necessary to move Shutter Speed Setting Lever (12) to a slower speed in order to bring Combined F-
stop and Light Value Setting Lever (6) within its free travel range.


2. Since the speeds on this shutter are not in multiple series, the lens opening numerals at shutter
speeds of 1/10 sec. 1/25 sec. 1/100 sec. and 1/250 sec. will not appear in the exact middle of the
Indicator Window. This, however, does not affect the correct exposure since, with the exception of
1;'500 sec., the scale intervals are in alignment and the shutter speed and lens opening are coupled
automatically for correct exposure.

 3. Because of the design of this shutter, the light value index should be ADVANCED to the next
 higher number when changing the shutter speed from 1/250 sec to 1,'500 sec. This, in effect,
 decreases the lens opening to the next higher F-stop value and compensates for over-exposure.
 Conversely, in changing from 1/500 sec. to1/250 sec., RETARD the light value index to the next
 lower number to compensate for under-exposure.

Example :

If the light value index is "14" for 1/250 sec., re-set to "15" for 1/500 sec,
shutter speed. This will automatically decrease the lens opening from f/5.6
to f,'8. Conversely, if it is desired to change from 1,'500 sec. to 1/250 sec.,
retard the Light Value by one index, i. e. from "15" to "14".



   Conventional Method of Determining Proper Exposure

In setting shutter speed and F-stop separately, move Shutter Speed Setting
Lever (12) until the red numeral is at the desired position in Shutter Speed
and F-stop Indicator Window (3).

To set the lens opening to the desired F-stop, move Combined F-stop and
Light Value Setting Lever (6) until the black numeral is at the desired
position in Shutter Speed and F-stop Indicator Window (3).

VI. VIEWING AND FOCUSING

One of the main advantages of a reflex camera is that it allows the
operator to look directly at the image appearing on the Focusing
Screen while turning Focusing Knob (24) to bring the picture-
subject into critical focus. There are four basic positions of holding
the camera for viewing and composing the picture; namely, waist
level, eye level, above eye level and ground level.


Focusing with the Reflex View-finder

                    Under most conditions the best method
                         of focusing this camera is to look at the
                     image on the Focusing Screen. The
                     image appearing there is identical to
                     what will be exposed on the film.


                            A. To Open the Focusing Hood


                                   1. Lift the rear edge of Focusing Hood (1) until it
                                springs up into full open position.


                              B. To Use the Magnifying Glass

1. Magnifying Glass (17) is raised into
                          position by pushing the upper edge of
                        Eye-level View-finder Frame Plate (2)
                        inwards. This will snap it into position.
                    The eye should be brought as close as
                         possible to Magnifying Glass (17) to
                         obtain "hair-line" focusing.

                       This glass has a magnification power of
                         2.5 times. It can be easily snapped back
                          into lowered position by a light pressure
                     on its outer edge.


Focusing with the Direct View-finder

In addition to the reflex view-finder method, it is also possible to
focus this camera by using Distance Scale (26) and composing the
picture through the Eye-level View-finder. Under this method, the
distance from the picture-subject to Taking Lens (8) is measured,
or estimated, and the resulting footage is read off on Distance
Scale (26) directly below the "2.8" figure on Depth-of-Field Scale
(27). This method is commonly used for fast-action photography.





To Use the Eye-level View-finder.


1. Raise Magnifying Glass (17) as directed above. 2. Press
Eye-level View-finder Frame Plate (2) all the way down
until it locks in the lowered position.

3. Sight through Eye-level View-finder Rear Sight (19) and
compose the picture.

4. To raise Eye-level View-finder Frame Plate (2) press Eye-
level View-finder Release Button (20).


5. Be sure to lower Magnifying Glass (17) before folding
Focusing Hood (l.)


 PARALLAX COMPENSATION LINE


When photographing picture-subjects at very close distances
(under 24 inches or so) the image on the Focusing Screen
covers an area much greater than that registered on the film.
This error is due to the difference in the vertical positions of
the Viewing Lens (5) and the Taking Lens (8) in relation to
the picture-subject and is called "parallax". The two short
lines etched horizontally on the upper edge of the Focusing
Screen mark the upper limits of the picture composition and
in taking close-up shots, care should be exercised to keep the
reflected image below these lines.





VII. DETERMINING THE DEPTH-OF-FIELD

A. What is Depth-of-Field ?


When a camera is focused on a picture-subject, there is a zone in front of and to the rear of the
picture-subject within which all photographed images are in acceptably sharp focus. Images falling
outside this zone become progressively blurred and out-of-focus. This zone of acceptably sharp
focus is called "depth-of-field", or sometimes "depth-of-focus" and is indicated in numbers of feet
measured from the film surface.

B. Factors affecting "Depth-of-Field"


Generalizing broadly, it can be said that "depth-of-field" is primarily determined by (1) distance and
(2) lens opening. Since it is axiomatic that the closer the picture-subject is to the camera, the
narrower the zone of acceptable focus, it is very important for beginners to exercise great care when
photographing at close distances.
As for the second factor, the larger the F-stop value (smaller lens opening), the greater the resulting
"depth-of-field" and conversely, a small F-stop value (larger lens opening) will decrease the zone of
sharp focus. To illustrate this relationship, it can be noted from the following Depth-of-Field Table
that at "infinity" distance and f/22 lens opening, the zone of sharp focus for this camera is between
10.7 feet and - (infinity) while for f/2.8 this zone decreases to a range between 84.8 feet and -
(infinity).
On the other hand, when the picture is taken at a relatively close distance of 5 feet from camera the
"depth-of-field" with f/2.8 opening lies between 7.4 feet and 5.3 feet while for the camera distance
of 30 feet, the "depth-of-field" covers a wider range; namely, between 22.2 feet and 46.4 feet.





C. How to Read the "Depth-of-Field" Scale

1. Read off the F-stop number on Shutter Speed and F-stop Indicator Window (3). (We
will assume for the purpose of this illustration that this number is "8")

2. Observe that there are two figures "8" etched on Depth-of-Field Scale (27)

3. Now read the figure (or approximation thereof) on Distance Scale (26) immediately
under the rear "8" (as seen by operator with camera in taking position). This is around
"7.5" and indicates that the near limit of the zone of sharp focus is 7.5 feet.

4. Next read the distance figure immediately tinder the
forward "8"
(again from operator's position)

This is "15" and means that is the far limit of the zone
of sharp focus is 15 feet.


5. Summarizing, the "depth-of-field" for this particular
exposure (F-stop 8, focusing distance 10 feet lies between 7.5
feet and 15 feet and signifies that any image lying within these
near and far limits is in acceptably sharp focus and images
which are closer or farther away from the camera will appear
progressively blurred on the finished print