Mamiya M645 AE Prism Finder User manual

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AE PrismFinder-
for MamiyaM645                         42u; -
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                             lnstructions

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    o SpecialFeatures
       1. The Mamiya AE Prism Finder employs a pentaprism which providt's a
         correct, upright image and inciudesa built-in electronicshutter control
          circuit which makes possibleaperture-priority,TTL automatic exposurr:
        metenng.
       2. The electronic shutter control mechanism is of a new type that instantly
        magneticallyrecordssignalscoming through the exposuremeter to the lC
        computer.
      3. Automatic exposure control  is possible by merely att?ching the AE
        Prism Finder to the camera. This means you get correct e).Fgsureevery
         time. All you have to do is set the aperture, focus and pressthe shutter
          reI ease.
      4. Exposure compensation is also easy by using the AE [-ock Button. This
         allows you  to  obtain correct exposure with  backlighting and other
          difficult conditions.
    o Specifications
      Viewfinder: Pentaprism type with correct, upright iinage.The magnification
          ratio is O.74X with the standard lens focused at infinity. A hot-shoe,
        eyecup and hot-shoe/eyepiececover are pro\r,'.j?d.
     Melering system: Center-weighted,averagedTTL open-aperturemetering.
      Control system: Aperture-priority, shutter-spee.dcontrol.
      Shutter coupling range: 2 -  1l'1000 second.
      Light measuringrange: (ASA 1OO)
       E V 2 . B 5- E V 1 7 w i t h f / 1 . 9 l e n sl f l 1 . 9 , 1 1 2 s e c . t o f1 1 1 ,1 / 1 0 0 0s e c . ) .
       E V 4 - E V l B w i t h t l 2 . B l e n s l f l 2 . 8 , 1 1 2 s e c . t o f 1 1 6 , 1 / 1 0 0 0s e c . ) .
      Film sensitivity range: ASA25 - 45A6400
     Aperture coupling range: Couplesat all aperturesof all availablelenses.
     Displays inside viewfinder: Shutter speeds are indicated by the exposure
        meter needle. Red under- and overexposuremarks are included and a red
        warning mark appearswhen the exposure meter is turned off .#   Switch dial: The AE Prism Finder is provided with an on/off switch with an
      AE lock built into its center.
    AE  lock: Pressing the AE  lock button  locks in the exposure value. AE
         control returns when the lock button is released.
     Power source: The meter receivespower from the camera battery.

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 Namesof Parts (Fis.1)
   1. Aperture ring coupling pin             8. Safety button
   2. Eyepiece/hot-shoecover               9, ASA dial
   3. Hot-shoe                        10. ASA window
   4. Eyepiece                                                                    ' t 1 . Power switch dial
   5. Eyecup                         1 2 . AE lock button
   6. Diopter correction lens retainer ring   1 3 . 500- 1 000 adjustment screw
   7. Finder releasebutton               1 4 . 5OO-1 000 adjustment key

 Cautions  Gig.2l
 The AE Prism Finder is adjusted for use with the M645 looos which has a
 maximum shutter speed of 1/1000 sec. Adjust as follows to use with the
 M645, which has a maximum shutter speed of 1/500 sec.
 Use the adjustment key  to  turn  the 500-1000  adjustment screw (13)
 counterclockwiseas far as it will go (approx.60"). This causesthe exposure
 meter needleto stop before the 1/1000 sec. position and display a maximum
 shutter speed of 1 /500 sec.
Usingthe AE Prism Finder
 The AE Prism Finder has an automatic locking device which allows it to be
 attached to the camera body by merely pressingit into position.
 The "double lock" system of the finder prevents accidental removal. The
 finder will not come off unless both the safety button and finder release
 button be pressedat the same time.
 Before attaching to the camera, first press in the finder releasebutton while
 pressingin the safety button.
 1. To attach the AE Prism Finder to the camera body, lift up the front part
 of the finder slightly and place the rear part on the camera. Next, pressdown
 firmly but gently on the front  part of  the finder and the locks will
automaticallyengageto hold the finder securelyin place (Fig.3).
The finder releasebutton  will then protrude to indicate that the finder is
firmly locked in place.
2. The aperture ring and exposure meter coupler (A) will connect auto_
matically when the aperture ring is rotated left and right (Fig.4).
o  Be sure to check the proper coupling.  lf the coupling pin cannot be
connected, use a small stick or other similar object to push the pin toward
the coupler.
3. set the @ mark on the shutter speed dial of the camera to the index
mark (B). The AE Prism Finder and camera body will not be electrically
connected if this dial is set to any other position; consequently,the exposure
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meter will not operate (Fig. 5).
4.  Pull the ASA dial of the finder out slightly and rotate until the desired
ASA value appearsin the window (Fig. 6).
5. Rotate the switch dial to the ON position to turn the AE Prism Finder
on. Always rotate until the click sound is heard (Fig.6 ).
o  When the switch is turned off, the exposure meter needle will remain
stationary in the red warning mark on the  right side of the finder. A
semi-circularred mark also appears in the upper left corner to indicate that
the exposure meter is turned off .
o  Always set the A/M lever of the lens to "A"; otherwise,correct exposure
will not be obtained. For the same reason,do not operate the depth-of'field
preview lever on the M645 10O0Swhen making exposures.
o  Use the battery check lamp to check battery condition before making an
exposure.
6. Rotate the aperture ring and set to a suitable aperture (about f/5.6 to
f/11 with ASA100 film  outdoors). The shutter speed will be determined
automatically by the AE Prism Finder. The shutter speed being used is
indicated by the exposure meter needle and is visible at the top of the field
of view when looking through the viewfinder. lncorrect exposure is indicated
when  the exposure meter needle enters the  red warning marks. An
intermediate shutter speed will be obtained if the needle indicates between
two values.
When the exposure meter needle enters the red warning marks
Overexposure is indicated when the exposure meter needle enters the red
warning mark on the left side. ln this case,set the aperture ring to a smaller
aperture (largerf/number).
Underexposure is indicated when the exposure meter needle enters the red
warning mark on the right. The aperture must be set to a larger opening
(small f/number).
The 500 position is the maximum shutter speedwhen the AE Prism Finder is
used with M645 cameras,which have a maximum shutter speed of 1/500 sec.
Overexposure is indicated when the exposure meter needle enters the
narrower red warning mark between the 500 and 1000 positions. The
aperture must be stopped down further in this casealso.

                                         Overexposure +-1
f 0 0 05 0 0 . 1 2 53'0 ' I    2   l s 2 s
         (250) (60)  (t5)  (4)           H                                                               r 000  500
                                                                                                                                                                                                          l >
                                                    Correct exposu

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     o  Since the AE Prism Finder uses TTL  metering, it  is not necessaryto
     consider exposure factors when using different lenses,filters, or for close-up
     photography.
     o  When making exposures,always keep the bye close to the finder eyepiece
      to prevent extraneous light entering and influencing the exposure values.
     o  When making an exposure with the eye away from the eyepiece,such as
    when using the self-timer or a cable release,remove the hot-shoe cover and
     place it over the eyepieceto prevent extraneous light entering the viewfinder
    and affecting the exposure metering.

     Cautions
     1 . Always set the shutter speed dial of the camera to the O position when
     usingthe AE Prism Finder.
      2. Turn the AE Prism Finder switch off when  it is not to be used for an
     extended period or when storing in a case, etc. Always rotate the switch
      until the click sound is heard. lf the switch is not turned off completely,the
     battery will be drained. (The finder can also be turned off by setting the
     shutter speeddial of the camera to any position other than O ).
      3. Always set the shutter speed dial to a position other than O when the
    AE Prism Finder has been removed. (The shutter will  lock in the open
     position if releasedwith the shutter speed dial set at the O  position. lf the
    camera is left in this condition, the battery will be exhaustedwithin several
    hou rs.)
      4. As explained in the beginning,set the 500-1000 adjustment screw to the
    500 position before using the AE Prism Finder with the M645, which has a
    maximum shutter speed of 1/500 sec. lf this adjustment is not made, the
     correct shutter speed can not be guaranteedwhen 1/1000 sec. is indicated
     by the exposure meter needle.
      5. When making "bulb"  exposures, rotate the shutter speed dial of the
    camera to the B position which is next to the O  mark. AE photography is
     not possible at this time becausepower will not be supplied to the finder.
     (The exposure meter needle will remain stationary in the red warning mark
    on the right side.)
      6. Four electrical contacts are provided on the top rear of the camera body
    and the bottom rear of the AE Prism Finder. Poor contact will result if theseI   contacts become oily or dirty, which would affect the operation of the AE
    mechanism. Always wipe these contacts gently with  a dry  cloth when
     attachingthe AE Prism Finder.
     7. When using extension rings, first attach the extension rings to the lens
    and then mount this assemblyon the camera body and connect the coupling

F'
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       pin.  (Note that the coupling pin of the extension rings can be rotated a full
      360"; therefore, if the ring is rotated when a lens is not attached, the coupler
       pin of the finder will be pushed fully to the right end. Further pressuremay
      causedamageso use caution.)
       8. When using the Auto-Bellows, use stop-down metering as explained in the
       instruction manual of the Auto-Bellows. When the aperture is stopped down,
       the shutter  will be released at  the  indicated shutter speed for correct
      exposure. Especially in the close-up photography, prevent extraneous light
      entering in the finder by keeping the eye close to the finder eyepieceor by
      using the eyepiececover.
    Usingthe AE lock button
     The AE lock button  is useful when intentional over- or underexposure is
      desired for specialeffects, etc., or under difficult lighting conditions (Fig. 7).
     The shutter speed indicated by the exposure meter needle in the viewfinder
         is held when the AE lock button is pressed.As long as the AE lock button is
      pressed,the shutter speed will remain the same even when the camera is
      pointed at a brighter or darker subject.
    Exposurecompensationunder difficult conditions
     When taking pictures under the difficult conditions described below,  it  is
      necessary to compensate the exposure in the same way as for normal
      average-metering exposu re meters.
     How  to compensate  exposure
      With a bright background
     When the background is exceptionally bright, as with strong backlighting,
      the subject will normally be underexposedand appear excessivelydark. In
       this case,move the camera close to the subject so that the bright background
     does not appear in the viewfinder and lock the shutter speed by pressingthe
     AE lock button. Move back into position and recompose the image in the
      viewfinder; then releasethe shutter to make the exposure. Do not releasethe
      pressureon the AE lock button until the exposure has been made.
      With a dark background
      Conversely,when the background appearsmuch darker than the subject, the
      subject will be overexposed.To compensateexposure in this case, proceed
      exactly the same as described above, going close to the subiect to eliminate
       the background from the viewfinder and lock in the shutter speed using the
     AE lock button.
      With strong backl ighting
     The shutter speed selected by the AE Prism Finder can be used with strong

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 backlighting if a silhouette effect  is desired. lf correct exposure of the
subject is desired, however, proceed as described for the above lighting
 conditions. In this case, the background will be overexposed and appear
whitish.
Flashphotography
Adjust the exposure mangally in flash photography. For electronic flash, set
the camerashutter speeddial to 1/60 sec. (or slower) and set the aperturein
accordance with  the guide number of the electronic flash unit and the
subject distance. For  details refer  to  the camera or  electronic flash
instructionmanual.
          -+D

                                                        ( When using a + diopter lens )

As an accessory, Mamiya offers diopter correction lenses that can be
attached to the finder eyepiece. Nearsightedand farsightedpersonswill find
these useful for obtaining accurate focus.
Diopter Correction Lensesare available in six strengths: -3, -2,  -1  , +1 , +2
and +3 diopters.
Before actually purchasinga Diopter Correction Lens at your Mamiya dealer,
first attach it to the camera and test to make sure that it correctly matches
your eyesight.
To attach, merely unscrew (counterclockwise) the diopter correction lens
retainerring (6) from the eyecup, insert the desiredcorrection lens making
sure it is positionedas shown in diagram,and replacethe retainerring. Then
slide the eyecup onto the eyepiece of the finder for easier,more accurate
f o c u s i n g( F i g . 8 ) .
Removingthe AE Prism Finder
Simultaneously press the safety button  (8) with  the right hand and the
finder releasebutton  (7) with the left hand. Next, remove the finder by lift-
ing upward (Fig. 9).
When the finder has been removed, the finder releasebutton  will remain
depressed.After removing the AE Prism Finder, always rotate the shutter
speeddial of the camera to a position other than @ .


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