Pentax Spotmeter V User manual

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O tens hood
O  f y e p i ece                                                          -(D
O Eyepieceadjustment ring                                           (D
O G r i p
(D Wrist strap                                                     (D
( D C al c u la t io nd ia l                                                  (D
(D Shutter speed scale
(D O iaphragm scale
(D Calculation table
( E w i p p l e f o r  t u rn in g
  A SA / l SO in d e x
( D t n d e x f o r D lN sca le
( D I nd e x f o r A S A / lS O sc ale
(D ASA/lSO scale
(D O ltrt scale
@ I nd e x f o r E V sca le
O  I R E s c a l e
@ t V  s c a le                                  @               www.orphancameras.com
@ Battery cap                                 @@ Tripod socket
@ Slit for wrist strap                              @

FEATURES

1. The minute 1o angleof view makes it possible
    to take accurateexposure measurements
   of a distant subject.
2. Wide rangeof light-measuringpossible:EV 1-19
     ( A S A / l S O 1 0 0 ) . S c a l eb y t h e u n i t o f 1 / 3 E V .
3. Can follow the fastestaction and work in the
   dimmest surroundingsbecauseof the
   instantaneousresponseof the Silicon Photo
   Diode.
4. Meter needlevisibleunder any lighting
   condition with a scaleilluminator.
5. Viewfinder angleof 21 degreescorresponding
    to that of a 35mm format camera lens of about
  120mm focal length with 1 .5x magnification
   makes it possibleto easilyobservesurroundings
   and details of the subject for easy searchof
   proper measuringspots.
6. StabilizerCircuit eliminatesLED  f lickersfor
   comfortable read-out.

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 BATTE R I ES

The Spotmeter V usesthree G-13 type alkaline           2 .  T h e   i n n e r s i d e o f  t h e c a p h a s a  ( - ) m a r k o n   i t .
or equivalent 1.5V silver-oxidebatteries.                      Insert three batteries in the opening so that the
1. As shown in the photograph,unscrewthe slotted         (+) sides of the batteries all face inward, and
   cap at the baseof the grip with a coin.                    the ends marked with  (-)  all face the side of
                                                                the cap marked  (-).  ne-tighten the cap.



                                                    2

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Precautions                                             Never throw used batteries into  f ire since they
o  M a k e s u r e t h a t p o l a r i t i e s o f a l l  t h e b a t t e r i e s a r e        may explode, causing unexpected damage or
    p r o p e r l y a l i g n e d . I n c o r r e c t p o l a r i t y a l i g n m e n t                         I n J u r y t o y o u .
   may cause unexpected damage to your                   Store batteries in a cool place, and out of reach
    e q u l p m e n t .                                                 o f c h i l d r e n .
o  R e p l a c e a l l b a t t e r i e s a t  t h e s a m e t i m e . D o n o t             Batteries are very sensitive to cold and
   mix battery brands, types or old batteries with           performance tends to deteriorate at temperatures
    n e w o n e s .                                              near freezing point. Performance  is restored as
.  R e m o v e b a t t e r i e s w h e n n o t u s i n g y o u r                  soon as batteries are brought back to room
    e q u i p m e n t  f o r a  l o n g  t i m e . B a t t e r i e s m a y  t e n d           temperature. Keep a set of batteries in a warm
       t o   l e a k  i f   l e f t  t o o   l o n g  i n y o u r e q u i p m e n t a n d            pocket when shooting  in cold weather to
   may cause serious damage.                                    s u b s t i t u t e  i f  t h e o t h e r s n o   l o n g e r p e r f o r m w e l l .
           +
                                                                                                      ( N e w b a t t e r i e s a r e p a c k e d a t  t h e  t i m e o f s h i p m e n t ,
                                                             but because of inherent self-discharging,
                                                     performance gradually deteriorates as time goes
                                                               by.  In such a case, replace the packed batteries
                                               w i t h b r a n d - n e w o n e s . )

OPERATION

1) Turn the ASA/lSO dial by usingthe two nipples     2l Looking through the eyepiece,turn the eyepiece
   to align the f ilm speed(ASA, lSO, DIN) In use      adjustmentring until the light levelscaleis in
   with the f ilm speedindex.                          clear focus.

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3 ) A i m   t h e S p o t m e t e r s o  t h a t a s m a l l c i r c l e  i n  t h e        4 l     l f   l i g h t  f r o m   t h e s u b j e c t  i s t o o   l o w  t o e n a b l e t h e
    c e n t e r o f  f o c u s i n g s c r e e n ( s e e i l l u s t r a t i o n )   i s           s c a l e t o b e r e a d , p r e s s t h e s c a l e i l l u m i n a t o r b u t t o n
   placed on a section of the subject to be measured.    o n  t h e s i d e o f  t h e g r i p o f  t h e S p o t m e t e r V a s y o u
   Depress the metering button and read the number            l o o k   i n  t h e e y e p i e c e . T h e u s e o f  t h e s c a l e
   o n  t h e   l i g h t m e t e r s c a l e i n d i c a t e d b y  t h e n e e d l e .               i l l u m i n a t o r w i l l m a k e   i t e a s y t o  r e a d  l i g h t  l e v e l s
                                                  E V 1 - B  o n  t h e   l e f t e n d o f  t h e s c a l e .





                                                                        o

5 )  T u r n   t h e o u t e r  r i n g o f  t h e m e t e r c a l c u l a t o r                    t h a t t h e n u m b e r 1 2 i s a l i g n e dw i t h t h e l a r g e
located on the side of the meter so that the              triangle (standardEV index).
n u m b e r  r e a d f r o m  t h e   l i g h t  l e v e l s c a l e i s a l i g n e d
w i t h   t h e   l a r g e t r i a n g u l a r  i n d e x a t  t h e b o t t o m  o f          6) When the EV readinghas been set, the proper
t h e c a l c u l a t o r  f a c e .                              exposurecombinationwill be indicatedon the
 l f , f o r e x a m p l e , t h e n u m b e r   i n d i c a t e d o n  t h e           two scalesat the top of the calculator.The "T"
l i g h t  l e v e l s c a l e i s E V 1 2 , t u r n   t h e o u t e r  r i n g s o         scaleindicatesshutter speed,the "F" scale
                                                    lensaperture (f-stop).
                                                    6

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F o r e x a m p l e :i f , u s i n gA S A / f S O 1 0 0 f i l m , t h e l i g h t
level is EV 4, the combinationsof tlG4 at shutter
speed4 minutes,of  f 116at 15 sec. (orangenumber),
or of tl1 .4 at 1lB sec.will all provideproper
exposure.Any other pair of corresponding
numberson thesescaleswill provideequally
correct exposuresettings.
While a great number of combinationswill be
indicatedon the calculator,only a portion of
them will be actuallyusablebecauseof limits on
diaphragmand shuttersettingsof the camera.
A suitablepair of numbersshould be chosenf rom
among the possiblecombinationsand transferred
to the camera.

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The spotmeterwill prove itself especiafly valuable
for measuringexposureof personsstandingunder
stagespotlightsand in similarlydifficult situations.
Measurethe gray 18 per cent standardreflection
card (Neutral rest card sold by Kodak) directly
or somethingelsewith a reflectivity ratio very close
to it (a Japanesemale'sface) to get the best results.

Averaging Method                                                                      lf the contrast between high lights and shadows
Measurethe high light (brightest)and shadow         exceedsthese ranges,measurethe light of at least
(darkest)areasand take the averageof the readings     three locations in the picture area and divide the
obtained. The best resultswill be obtained if the       sum of readingsby the number of locations
difference between the high light and shadow is        measuredto obtain an averagevalue.
no greaterthan the reproduciblecontrast ratio of       Set this averagevalue to the large triangular index. lf       ,r
the film.                                              the difference is more than 5 EV's, the high light areas
For color reversalfilm and black-and-whiteprints      beyond the film's reproducibility rangewill be
it is within 5 EV numbers. With color prints, the        overexposed,or the shadow areaswill be under-
n a r r o W e r d i f f e r e n c e w i | | r e n d e r a s o f t t o n e . e x p o s e d . B y t h i s m e t h o d , h o w e v e r , o n e w i | | o b t a i n
                                                          correct exposure for the greatest area of the
                                                        picture as a whole.

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For example,the exposurevaluesin the high light
and shadowin the picture on the right are 12 EV's
and 9 EV's respectively,making only a 3-EV difference
becauseof a low contrast cloudy weather condition.
The averagevalue is 10.5 EV's which is namely
the correct exposurevalue and happensto
correspondto that of the bamboo leaves.

The Pentax Spotmeter is provided with an lR E
Scalewhich is very usefulfor televisionf ilming and
movie making, as well as generalphotography to
conf irm the light levelsof the upper and lower
brightnesslimits (High light and shadow reading
meth ods) .
The latitude of reversalf ilms and movie f ilms used
for TV broadcastingis said to be within 5 EV's
11:32in contrast ratio). The IRE scalerangesf rom
1 to 10 (dividedinto ten fractions,but not equi-
distantly) in accordancewith the contrast ratio of
5 E V ' s .
There is a scaleshowing 1 - 10 with the EV index
in between.

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 f n d e x 1 0 ( 1 O O %I R E ) i n d i c a t e st h e l i m i t o f  t h e         obtained in exposure measurements.The large
high light detailsreproduciblein the picture, the         triangular index between 3 and 4 is the EV
upper brighnesslimit, and is calledthe "White          Index, which shows the averageof optimum f ilm
level."                                        exposurelevels(light level obtained usingstandard
Index 1 llo% IRE) shows the.minimum darkness       reflecting surfacewith reflectivity ratio of 18%).
of shadowdetail reproducibleon the f ilm. This is      The figure "1:32" at the extreme left of the scale
calledthe "Black level." The intermediatenumbers     indicatesthe contrast ratio between IRE scale
9 - 2 (90 - 2oo/oIRE) indicateintermediatecontrast   1 and 10, correspondingto a 5-EV range.The IRE
ratios basedon the 100% "White level" corresponding  scalesfrom 1 to 10 cover the 5 EV latitude range
Index 10. Theseindicesrepresentdivisionsof             of reversalphoto f ilms and movie f ilms usedfor
the lineary gray scale.                         TV broadcasting.See the following table for
*  I R E U N I T                                        your reference;
IRE units provide a means for the percentage-wise                                                     Index 10  '-+ +2.3EV  ----r-comparisonof energy.The maximum energyvalue                                                            8   - + + 1 . 7 E V       Iis taken to be 100% and energy levelstaking this                                                            5   --' +0.7F;  EV 5  ReProduciblerangemaximum as a standardsare expressedas percentages                                                            2   *  -1.3Ev  fi:32l, (Latitude)of maximum level.This method is used in radio                                                            1   --+ -2.7E;          Icommunicationsto compare signalvoltages,but is
also applicableto the comparisonof light energy

High Light Reading Method                       The light level read at the high light portion of
This is a method for which the Pentax Spotmeter       a subject such as white wall, white paper, etc. is
is uniquely adapted.In this case,the light levelof       alignedwith the index 10 of the IRE Scale,so that
the subject'shigh light is made the basevalue for       proper exposureis obtainedfor the best rendition
exposuresetting.This method was developedfor         of white color. With color film, only those shadow
televisionfilming, but is just as usefulfor still and       detailswith a light level readingfalling to the right of
motion picture photography.As previously           index 1 of the IRE scale(black level)will be
mentioned,the maximum reproduciblecontrast       reproduced.Areas with a light value falling below
ratio differs accordingto film type, but generally      index 1 willappear as unrelievedblack.
speakingthis ratio is the same for color film as for      Therefore,when the light levelof the high light
televisionbroadcasting,namely about 1:32. The       has been set on index 10, if important shadow
ratio for black and white film is approximately          detail has insufficientlight to bring it above index
1:100. To use this method, the light levelof the          1, it will haveto be given additional illumination
high light is first determined,and this EV value          until its light level readingdoes exceedthis index 1.
is taken as the upper exposurelimit. By doing this
the optimum exposure will be basedon the high
light areas.


1 6

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Shadow Reading Method                        Read the light value of the shadow area needed to
The reverseof the high light reading method, this       reproduce,and set it to the index 1 on the IRE
method givesan optimum exposure basedon the       Scaleto obtain proper exposure.
shadowareas.Shadow readingis employed for            In this case,areasof light value up to index 10 on
bringing out detail of personsphotographed with        the IRE Scalewill be reproducibleon color f ilm.
backlighting,and for  f ully reproducingshadow        Areas of light value falling above index 10 will be
detail in picturestaken at night.                  washedout.
When ordinary light meters are used to set exposure    Consequently,if important high light detail has
for eveningor nighttime sceneswhich do not           a light levelfalling above index 10 when shadow
includebright subjectssuch as neon or other             light level has been set accordingto index 1, it
lighting,the resultingphotographhas the same           will be necessaryto reduceillumination of the
appearanceas a daytime scene.Using this shadow-      high light area, or to reduce the reflectivity of
readingmethod helps you obtain correct exposure      the high light point, until its light levelfalls below
that will make eveningor night sceneslook                                i n d e x 1 0 .
exactly as they are.

C I N E C A M E R A S A N D S P O T M E T E R

Pentax Spotmeter can be effectively used to
obtain ideal brightnessor luminancebalancefor
intendedcolor rendition or correct exposure
results,especiallyunder difficult situations,when
shootingwith a cine cameraor video camera.

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Cine lndex
The operation of the spotmeter for movie camera
differssomewhatf rom that of still photography.
The shutter speedof movie camerasis determined
by cameratype, the shutter openingangle,and
whetherthe camerasbeing usedfor high or low
speedphotography.
The standardshutter speedof the ordinary 35
a n d 1 6 m m m o v i e c a m e r ai s a p p r o x i m a t e l y1 / 5 0
of a second (24 f ramesper second).ffris speed is
marked in yellow on the Shutter SpeedScale
betweenthe 1/30 and 1/60 sec.divisions.
Therefore,when usingthe meter with thesecameras,
the apertureopeningis found on the Aperture Scale
below this mark.

--l
 II pnEcAUTIoNSBY SHooTING SUBJEcTS

Movie Screen                                   Exposure Factor
24 lrames per second are projected on the movie         Light on the film plane becomesweaker in short
screenand during the time of switching a frame to       distancephotoshooting, becausethe helicoid of
another, there is no image projection. On such          the taking lens is fully extended to result in
subjectsthe spotmeter shows somewhat lower          a longer lens/film plane distance than the focal
exposurevaluesbecauseits display function does        length. This meansthat in actual shooting sessions
not catch up with such changes.                    you must increasethe exposure value by 1.1 -  1.5
TV Screen                                         times (which is, however. taken account of in
 It also shows lower exposure valuesas in the above      the caseof a SLR camera at the time of its design
casedue to the TV scanninglines.                         to avoid such a complicated compensation).
In either way, it is diff icult to correctly measure
such a light that is quickly switchingon and off
alternately (also in caseof mercury lamps and
some fluorescent lamps).

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  Size of the 1" metering angle of the Spotmeter V relative to the field of vision obtained with various lenses
  used with 35mm cameras.       *"1---1""[  ""f-"--l ""[-"-  "---1      --l       'ou"l-.-l*"l-;--l'oo"[""1-.                     ol
'*"Fl-*]-l*"]         o              I'ooo"O_1
                                                                                      23

Zero Adjustment
When the light metering button is not depressed,the
indicatorneedleseenthrough the f inder should
rest on the small black circle to the right of the
light levelscale.lf the needleis off this black
circle, turn the small screw locatedjust above the
battery checker button B with a screwdriver
either right or left until the needleagainpoints to
t h e b l a c k c i r c l e .