Film cameras
Mamiya M645 CdS Prism Finder User manual
User manual for Mamiya M645 CdS Prism Finder. 13 pages in English. Read the original PDF, download or print a copy without registration.
13 pagesEnglish0.9 MB PDF
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Document details
- Brand
- Mamiya
- Model / document
- Mamiya M645 CdS Prism Finder
- Document type
- User manual
- Language
- English
- Pages
- 13
- File size
- 0.9 MB
- Category
- Film cameras
- Document date
- Not specified in catalog
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Page 3 · Read text
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Namesof Parts
o Special Features
1. Apertureringcouplingpin1. The CdS Prism Finder is an eye-levelfinder with a built-in 2. Hot-shoeCdS exposure meter for accurate exposure measurement. 3. Batterychambercover2. lt couples to the aperture when attached to the camera. 4. Eyecup3. An exposure meter indicatorneedle is visible in the view- 5. Dioptercorrectionlensfinder to indicate correct exposure. retainerring
o Specifications 6. Eyepiece 7. Finderreleasebutton
Viewfinder: Unreversed, laterally correct image; 8. Shutterspeeddial
0.74x magnification with standarci 9. ASAwindow
BOmm lens at infinity; built-in hot 10.ASA dial
shoe and equipped with an eyecup. 11.Powerswitch
Metering Syitem: Center-weight TTL full-aperture,
zero-methodvia indicator needle.
MetercouplinsRanse: lensand100ASAfilm) , ExlJfj
(l/1.9,1/2sec.- f/11,1/1000sec.)
(withf/2.8 lens and 100ASA film)
,,1,,EV4- 1B
' ,,,,.. 1,,r,;(t/2.8,1/2sec.- t116,1/1000sec.)
ShutterSpeedRange:1/1000-1 sec.
,, ASA Range:25 * 6400
(Aperturecouplingin the entire .
range)
PowerSource:One 1.5V silveroxide batteryView original page 3Page 5 · Read text
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o Inserting the Battery
1. Remove the battery chamber *When the finderis not usedfor
cover by rotating it counter- a long periodof time,removethe
clockwise with the aid of a coin. batteryand store it in a cool, dry
2. The underside of the battery place.
chamber cover bears a + mark. * Never throw used batteries
Be sure to have the + marks of into a fire, or attemptto charge
battery and chamber cover face a battery.
each other as the battery is in-
serted. Then securely retighten
battery chamber cover.
*Wipe battery with a soft cloth
before inserting into battery
chamber, as a soiled battery
This finder utilizes a 1.5V silver may fail to make, or maintain,
oxide battery (Eveready S-76, proper contact.
Mallory MS-76 or equivalent) as There are four electrical contacts
the power source. on the upper, rear plane of the
camera body and on the bottom
plane of the finder. Oil or finger-
prints on the contacts will result
in faulty power conduction.
Always completely wipe off oil
or dust with a clean cloth before
attaching the finder.View original page 5Page 6 · Read text
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Methodof Use
Precaution:
Prior to attachingthe finder to Do not leave both white dots
the camera, confirm that the aligned by turning the button
white dot on the finder release while the finder is attached to
buttonis pointingupward. the camera.The finder may be-
lf the white dot on the button is come detachedwhenthe button
alignedwith the white dot on the is occasionallydepressed,pos-
finder,by depressingthe button siblycausingdamage.
andremovingyour f ingerfrom it, lf you depress the button to
the white dot on the button will pointthe white dot upwardwhile
automaticallypoint upward. ln the finder is attached to the
this condition,the buttoncannot camera,be sure to depressthe
be depressed; consequently, finderagainstthe camerabody;
thef inderwill notbe accidentally 1. Placethe rear part of the find- otherwisethe finderwill not be
detachedfrom the camera. er on the camera body while lockedinto place.
holdingthe frontpart of the f ind- *Always set the AM Leverof the
er slightlyupward.Slidethe rear lens to "A", otherwisecorrectex-
part forward until it stops and posure cannot be obtained. For
gently lower the front part of the the same reason,do not touch
finder onto the camera body the depth-of-field preview lever
then firmly depress the finder of the M645 10005 whenever
making an exposure measure- downward.lt will then lock into
ment. place.View original page 6Page 8 · Read text
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exposure meter indicator nee-
dle visible in the viewfinder is
centered between the two
brackets visible on the right-
hand side of the focusing
screen.
lf the indicator needle cannot
be centered even after rotating @ the aperture ring as far as it will
go, the exposure must be ad-
justed by rotating the CdS Prism
5. Set the shutterspeed dial on Finder shutter speed dial. lf the
the camerabody to the desired indicator needle is too high, set
speed, and then set the shutter the shutter speed dial to a
speed dial ol the CdS Prism shorter ("faster") speed; if too
Finder to the same speed. low, set to a longer ("slowe/')
(Examples of recommended speed. After adjusting the shut-
shutter speeds to use with 100 ter speed dial of the CdS Prism
ASA film would be 1/250, or Finder, if the indicator needle is
1/125sec. outdoorson a sunny slightly off-center, make f inal
day,1/125or 1/60 sec. outdoors adjustments with the aperture
on a cloudyday, and 1/30 sec. nng.
whenworkingindoors.) 7. Whenever changing the set-
6. To set the correct exposure, ting of the shutter speed dial of
rotatethe aperturering untilthe the CdS Prism Finder to adjustView original page 8Page 9 · Read text
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for exposure,do not forget to set intermediate positions, but al- varies in accordancewith the
the shutter speed dial of the ways set the dial to a click-stop. extensionof the auto bellows,
camerabody to the same setting. lf the indicator needle cannot extension rings, etc. Conse-
Afterthe above steps have been be perfectly centered with the quently,for accurateresultsbe
completed(centeringof the in- shutter speed dial at a click- sure to first focus on the subject
dicator needle),exposure set- stop position, make final adjust- before taking an exposure
ting shouldbe correct,and the ments with the aperture ring. measurement.
picturemay be taken. *To prevent extraneouslight
o Conect Exposure from enteringthe eyepieceand
. Aperture Priority Method Measurement influencingthe exposure read-
1. When desiring to set the * The TTL metering system of ing, keep your eye close to the
aperturefirst, set the aperture your CdS PrismFindermakesit eyecup when making an expo-
ring to the desired f/stop, and unnecessaryto consider such sure measurement.
then adjustfor exposureby ro- factors as the differencein an-
tating the shutterspeed dial of gle of view of interchangeable
the finder until the indicator lenses, filter factors, or expo-
needleis centeredbetweenthe sure increase for macrophoto-
brackets. graphy.(For accurateexposure
2. Check the settingof the find- measurement when taking
er shutter speed dial, and set close-ups,be sure to carefully
the same setting on the shutter read the instructionspacked
speed dial of the camera. with the auto bellows, reverse
*When adjustingfor exposure ring,etc.)
with the CdS PrismFindershut- * In macrophotography,the
ter speed dial, do not use any amountof light reachingthe filmView original page 9Page 10 · Read text
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o MeterCoupling Range
The range of usable shutter *To conserve battery power, is removed from the camera,
soeeds varies in accordance keep the exposure meter switch the exoosure meter is auto-
with the film speed (ASA).As the set to OFF whenever.the meter matically switched off because
shutter soeeds shown in the is not in use. Even when forget- of the small safety switch built
shaded area of the diagram be- ting to set the switch to OFF, into the bottom of the finder.
low are beyond the range of the whenever the CdS Prism Finder
meter, the shutter speed dial is
provided with a safety lock to
prevent one from entering the
non-usable zone. For example. Usable Shutter Speeds (unshaded area)
it can be seen f rom the diagram
that 1/B sec. is in the non-usable ShutterSpeeds(sec.)
A S A 1 l l l l l 1 l lzone when using film rated at 'l"lllll,:lJ' 6 a l r 2 s l z s o l s o o l r o o o800 ASA (or higher); conse- 25
quently, when the ASA dial of
5 0
the CdS Finder is set to 800, the
100shutterspeed dial cannot be set
to 1/B sec. 200
400
8 0 0 %
1 6 0 0 %View original page 10Page 11 · Read text
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DiopterCorrectionLenses
4_* (When Diopter Lenses are used)n
(When + Diopter Lensesare used)
As an accessory,Mamiyaoffersdioptercorrectionlenseswhichcan
be attachedto the PrismFinders.Nearsightedand farsightedper-
sonswill find these accessoriesusefulfor obtainingaccuratefocus.
DiopterCorrectionLensesin six strengthsare available,-3, -2,
-1, +1, +2, and +3 diopters.
Merelyunscrew(counterclockwise)the dioptercorrectionlens re-
tainerring(5)from the eyecup,insertthe necessarycorrectionlens,
wherethe lensdirectionmustconformto thoseshowninthe diagram,
and replacethe retainerring.Thenslidethe eyecupon the eyepiece
of the finderfor easierfocusing.View original page 11Page 12 · Read text
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o Exposure Compensation under Special Photographic Conditions
When photographingunder such specialcon- o Compensation Hints
ditions as described below, it is necessaryto 1. For strongly back-lit subjects outdoors, set
somewhat compensate the exposure as re- the exoosure to F1.
quired for conventional average-meteringex- 2. To photograph a person indoors, seated next
posure melers. to a window and strongly back-lit, set the ex-
The brackets visible in the viewfinder not only DosureIo +2.
indicatecorrect exposure, but are also notched 3. When photographinginteriors,to compensate
to indicate t 2 f/stops (see diagram) to simplify for the bright interior lights,set the exposure to
exposure compensation for unusual lighting. +1 or 12.
When the exposure meter switch is set to OFF, 4. When copying white documents, set the ex-
the indicator needle rests at the bottom oosi- posure to +2.lf a standard gray card is used to
tion. determine exposure,no correctionis necessary.
5. When photographing a brightly lit subject
against a dark background,such as a night club
'1
+ 2 performer, set the exposure to or 2
_ l a 6. Brightly lit night scenes, such as city streets,
correcl exposure are usuallyrendered most naturallywith the cor-
rect exoosure.
7. When photographingextremelydark subjects
OFF (e.9. close-up of a black cat), set the exposure
t o 1 .View original page 12Page 13 · Read text
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Precaution:
When using Auto Extension Rings, first attach
the extension rings to the lens; then mount the
assembly on the camera body and finally con-
nect the coupling pin.
(Note that the aperture ring coupler of the exten-
sion rings is rotatablethe full 360".lf the coupler
ring is rotated when the lens is not attached, the
coupling pin will be fully pressedto the right end.
Should pressing force be furtherapplied, the
coupling.pinmay be damaged. Exercisecare!)
P r i n t e d r n J a o a nView original page 13From the M. Butkus archive. Original publisher and archive notices are retained.
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PDF verified 2026-10-10.