Pentax Digital Spotmeter User manual

LISPECIFICATIONS

  MeasuringRange:         ( 1 0 0 A S A ) E V 1 - 2 0 ( E V 2 0 d i s p l a y e da s " 0 " ) .
  Scales:            A S A , 6  - 6 4 0 0 ; S h u t t e rS p e e d , l l 4 O O Os e c .- 4 m i n . ; A p e r t u r e , fl 1 - 1 2 8 ;
                    E V N u m b e r , l - 1 9 - 2 1 3 ;l R E , 1 - 1 0 .
  MeasuringAngle:      1 " _
 MeasuringDistances: F r o m a b o u t 1 . 5 m t o  i n f i n i t y -   f i x e d f o c a l l e n g t h .( F o c u s i n gd o w n t o a b o u t
                       1 m p o s s i b l eb y s c r e w i n gt h e e y e p i e c eo u t a s f a r a s i t w i l l g o ) .
  MeasuringMethod:    Spot rrreasuringof ref lected light. (Meter switcheson when button pressed).
 ExposureRead-Out:   L E D d i g i t a ld i s p l a yo f E V N u m b e r s( 1 0 0 A S A ) , a n d u p t o  t w o d o t s ( e a c ho f
                  w h i c h e q u a l s+ 1 / 3 E V ) .
  PhotosensitiveCell:   S i l i c o nP h o t o D i o d e
 Power Source:      One 6V silveroxide battery (No. 544 or equivalent)or No. 537 alkaline battery.
  Battery Check:       F a i l u r eo f L E D d i g i t a ld i s p l a yt o  i l l u r n i n a t ei n d i c a t e bs a t t e r y n e e d sr e p l a c i n g .




                                                                                                                   - \

Viewf inder:          Pentaprismtype with unreversed,laterallycorrect image.Objectiveand
                    eyepiecelensesSuper-Multi-Coatedand pentaprismspeciallysilveredfor
                          brilliant viewfinder image.Even illuminationachievedwith f inely grooved
                      fresnel lens.1o spot indicatedin centerof viewfinder, and largeLED Panel
                    appearsatthe bottom. Viewf inder coveragesimilar in shapeto that of a 35mm
                  SLR, and with a diagonalf ield of view of 26" ,horizontal f ield of 22" ,and
                        verticalf ield of 14",adjustableeyepieceof -2 Lo +1 diopter.
F ilter Size:           4 0 . 5 m m .
Dimensions:          4 4 m m ( D ) x 1 4 4 m m ( H ) x B 3 m m ( W ) .
Weight:            25Bg (with battery).
Additional:          Equippedwith Tripod Socket, suppliedwith case,Wrist Strap, battery, and
                   Lens Cap.


                            www.butkus.us

EyepieceAdjustment
Battery Chamber Cover                                               Lock Ring
Tripod Socket                                                         Eyepiece Lens
Wrist Strap Eyelet                                                    Eyepiece(R ubber) F rame

EyepieceAdjustment
Battery Chamber Cover                                                Lock R ing
Tripod Socket                                                       EyepieceLens
Wrist Strap Eyelet                                                   Eyepiece(R ubber) F rame





                            www.butkus.us

ISPECIALFEATURES

1. Small enough to be pocketable.                     9. Digital displayexceptionallylargefor viewing
2. Light enough to carry anywhere.                   ease.
3. Strongly resistantto shock (no moving parts in    1 0 . D i g i t a ld i s p l a y( E V N o . , 1 0 0 A S A ) g i v e n i n 1 / 3
   exposuremeasurementsystem).                EV stepsto match the ASA, Shutter Speed,
4 . L E D d i g i t a ld i s p l a yv i s i b l eu n d e r a n y  l i g h t i n g        Aperture, and EV No. Scalesfor preciseand
   co nd it io n.                                     easyto make settings.
5. Can follow the fastestaction and work in the     1 1 . T h e m i n u t e 1 o a n g l eo f v i e w o f  t h e D i g i t a l
   dimmest surroundingsbecauseof the               Spotmeter is equivalentto a 40 power ultra-
   instantaneousresoonseof the Silicon                telephoto lens,making it possibleto take
   Photo Diode.                                     accurateexoosure measurernentsof
6. Human engineeredfor the perfect grip and            a distant subject.
   o p t i m u m h a n d l i n ge a s e .                        12. Only with a spotmeter is it possibleto separately
7. Objectiveand eyepiecelensesSuper-Multi-         measureallof the tones of a given subject,from
   Coatedand pentaprismspeciallysilveredfor           the brightesthighlightto the darkestshadow.
   b r i l l i a n tv i e w i n g .
8 . S t a b i l i z e Cr  i r c u i t e l i m i n a t e sL E D f l i c k e rf o r
   comfortableviewino.

OUTLINEOF OPERATINGPROCEDURE

Illust.T & B, While looking through the viewfinder     readjustthe EyepieceAdjustment Lock R ing to
 ( @ ,   i l l u s t .B ) a t a d i s t a n to b j e c t ,r o t a t e c o u n t e r -      a m i d w a y p o i n t s o t h a t b o t h t h e d i g i t a ld i s p l a y
c l o c k w i s et h e E y e p i e c eA d j u s t m e n tL o c k R i n g ( @ ,     and 1o spot appearreasonablysharp.
 i l l u s t B. & 9 ) u n t i l t h e s m a l l c i r c l ei n t h e c e n t e ro f         Illust.9, Af ter adjustingthe eyepiecef or maximum
t h e v i e w fi n d e r ( i o s p o t ) a p p e a r ss h a r p .N e x t ,          sharpness,hold the rubber EyepieceFrame
s q u e e z et h e M e t e r i n gB u t t o n ( @ ,   i l l u s t .1 1 ) t o           s e c u r e l y( @ ,   i l l u s t .9 ) s o t h a t i t d o e s n o t m o v e ,
d e t e r m i n ew h e t h e rt h e d i g i t a ld i s p l a y ( i l l u s t .7 )        and lock it into placeby rotating the Eyepice
alsoappearssharp.lf  it does not appearsharp,        A d j u s t m e n tL o c k R i n g ( @ ,   i l l u s t .g ) c l o c k w i s e
7                                                   8
   7





      \

u n t i l  i t s t o p s . W h e n s o m e o n e e l s e i s t o u s e t h e                         I l l u s t . 1 1 , W h i l e h o l d i n g  t h e s p o t m e t e r u p  t o y o u r
s p o t m e t e r , r o t a t e  t h e E y e p i e c e A d j u s t m e n t  L o c k         e y e , a l i g n t h e 1 " s p o t  i n  t h e c e n t e r o f  t h e v i e w f i n d e r
R ing cou nterc lockw ise to loosen eyep iece,            w i t h   t h e p a r t o f  t h e s u b j e c t y o u w i s h  t o m e a s u r e .
r e a d j u s t e y e p i e c e , a n d   l o c k   i t   i n t o p l a c e o n c e a g a i n .     S q u e e z e t h e M e t e r i n g B u t t o n a n d a n L E D d i g i t a l
I l l u s t . 1 0 , A l i g n  t h e A S A N o . o f  t h e  f  i l m b e i n g           d i s p l a y w i l l a p p e a r . I n   i l l u s t J ,  I h e d i g i t a l d i s p l a y
u s e d w i t h  t h e g r e e n A S A    l n d e x  ( @ ,     i l l u s t . 1 O ) b y                     i n d i c a t e s 1 3 - 2 1 3 E V ;   i t a s i n g l e d o t a p p e a r e d ,  i t
r o t a t i n g t h e A S A / S h u t t e r S p e e d D i a l  ( @ ) w h i c h       w o u l d    i n d i c a t e 1 3 - 1 1 3 E V , a n d   i f n o d o t a p p e a r e d ,
 i s c l o s e t o  t h e  f r o n t o f  t h e   l e n s @     . T h e  f  i g u r e s                       i t w o u  l d  i n d i c a t e e x a c t l v 1 3 E V .
o f  t h e A S A S c a l e a l s o a p p e a r  i n g r e e n .
I                                      1 0                               1 1




                            www.butkus.us

C I N EI N D E X
The operation of the spotmeter for movie cameras
differs somewhatfrom that of still photography.
The shutter speedof movie camerasis determined
by cameratype, the shutter opening angle,and
whether the camerais being usedfor high or
low speedphotography.
The standardshutter speedof the ordinary 35 and
16mm movie camerais approximately 1/50 of
a second (24 frames per second).This speed is
marked in red on the Shutter Soeed Scale between
the 1/30 and 1 /60 sec.divisions.Therefore, when
usingthe meter with thesecameras,the aperture
opening is found on the Aperture Scalebelow
t h i s m a r k .
With Bmm movie cameras,the Super-Band Single-B
types take 1B frames per second,and the Double-B                      'ltype takes 6 f rames per second. In both cases,
the proper apertureopeningwill be found on www.butkus.usthe
Aperture Scalebelow the 1/30 sec.mark.

T h e   i n t e r m e d i a t e n u m b e r s 9  - 2    ( 9 0 -  2 0 %  I R E )
 i n d i c a t e c o m p a r a t i v e b r i g h t n e s s b a s e d o n  t h e 1 O O %
" W h i t e    l e v e l . " T h e s e  i n d i c e s r e p r e s e n t d i v i s i o n s o f
t h e   l i n e a r g r a y s c al e .
T h e   l a r g e o r a n g e t r i a n g u l a r  i n d e x b e t w e e n 3 a n d
4   i s t h e S t a n d a r d  I n d e x ,   i n u s e o n m o s t   l i g h t m e t e r s ,
w h i c h s h o w s t h e a v e r a g eo f o p t i m u m   f  i l m e x p o s u r e
 l e v e l s ( l i g h t  l e v e l o b t a i n e d u s i n g s t a n d a r d  r e f l e c t i n g
s u r f a c e , r e t l e c t i v i t y r a t i o o f 1 B % ) .
T h e  f  i g u r e " 1 : 3 2 "  a t  t h e e x t r e m e   l e f t o f  t h e s c a l e
 i n d i c a t e s t h e c o n t r a s t r a t i o b e t w e e n   l R E s c a l e 1
a n d 1 0 T h e  I R E s c a l e sf r o m 1  t o 1 0 c o v e r 5   l i g h t
 l e v e l n u m b e r s S i n c e a n   i n c r e a s eo f o n e E V n u m b e r
r e p r e s e n t sa d o u b l i n g o f   l i g h t  l e v e l , t h e c o n t r a s t
ratio  is 1 :32 Qs = 32\

                           www.butkus.us

i VAR]OUSII4ETHODSOF EXPOSUREREAD]NGS                                                                                                                                                 l

Methods of expo6urereading include the half-         The spotmeter will prove itself especiallyvaluable
tone reading method, the avoraging method, the           for measuring exposure of persons standing under
highlight reading method, and the shadow              stagespotlightsand in similarly diff icult situations.
readingmethod.                                    Since the half-tone method measuresin half-tone
                                                          only,  it is very simple, but the clue to successlies
                                                              In the way in which the half-tone ref lectivity ratio                                                                                                                                                                                                                                                                     iHALF TONE READING METH0D                          is measured.Measurethegray 18 percentstandard
Center the 1" spot on a half-tone area of primary         ref lection card directly or else something with                    !
interestand take the readingfor that point. lf, for       a reflectivity ratio very close to  it to get the
example, the sub.iectis a peison, aim the 1" spot        best results.                                                                                  t
at his or her Jace lf the subject is an object or                                                                                                                              I
a landscape,selectan areaof averagetonal quality     AVERAGING METH0D
and place the 1' spot in that area.                  Measurethe highlight (brightest)and shadow
After readingthe light level,align this number  .          (darkest)areasand take the averageof the
with the IRE Standard Index. Select an appropriate     readingsobtained. The best resultswill be obtained
set of valuesfor shutter speedand aperture opening          if the difference between the highlightsand
from the two scalesin the center of the exposure      shadows is no greater than the reproducible
calculator.                                         contrastratio of the f ilnl. For black and white

1 A

r e v e r s a lf  i l m  t h i s d i f f e r e n c e  i s a p p r o x i m a t e l y 7 E V
n u m b e r s ; f o r c o l o r  r e v e r s a lf  i l m a n d b l a c k a n d
w h  i t e p r i n t s   i t   i s a p p r o x  i m a t e l y 5 E V n u m b e r s .
W i t h c o l o r p r i n t s , t h e d i f f e r e n c e  i s  l e s s t h a n 5 E V
n u m b e r s .  l f  t h e c o n t r a s t b e t w e e n h i g h l i g h t s a n d
shadows exceeds these ranges, measure the light
o f a t   l e a s t t h r e e   l o c a t i o n s  i n  t h e p i c t u r e a r e a a n d
d i v i d e t h e s u m o f  r e a d i n g s b y  t h e n u m b e r o f
 l o c a t i o n s m e a s u r e d t o o b t a i n a n a v e r a g e v a l u e .
S e t t h i s a v e r a g ev a l u e b y  t h e S t a n d a r d  I n d e x .  I n
t h i s c a s e t h e h i g h l i g h t a r e a s b e y o n d  t h e  f  i l m ' s
r e p r o d u c i b i l i t y r a n g e w i l l b e o v e r e x p o s e d , o r
t h e s h a d o w a r e a s w i l l b e u n d e r 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 l l h a v e o b t a i n e d c o r r e c t
e x p o s u r e f o r  t h e g r e a t e s t a r e a o f  t h e p i c t u r e
a s a w h o l e
                            www.butkus.us

F O R T H E S P E C I A L I S T


T h i s  i s a m e t h o d  f o r w h i c h  t h e P e n t a x D i g i t a l
S p o t m e t e r   i s u n i q u e l y a d a p t e d .  I n  t h  i s c a s e , t h e
 l i g h t  l e v e l o f  t h e s u b j e c t h i g h l i g h t s a r e m a d e
t h e b a s e v a l u e f o r e x p o s u r e s e t t r n g T h  i s m e t h o d
w a s d e v e l o p e d f o r  t e l e v i s i o n f  i l m i n g , b u t   i s j u s t a s
u s e fu I f o r s t i l l a n d m o v i n g p i c t u r e p h o t o g r a p h y A s
p r e v i o u s l y m e n t i o n e d , t h e m a x i m u m  r e p r o d u c i b l e
c o n t r a s t r a t i o d i f f e r s a c c o r d i n g  t o  f  i l m  t y p e , k r u t
g e n e r a l l y s p e a k i n g t h i s r a t i o  i s t h e s a m e f o r c o l o r
 f  i l m a s f o r  t e l e v i s i o n b r o a d c a s t i n g ,a b o u t 1 " 3 2 '
T h e  r a t i o f o r b l a c k a n d w h i t e  f  i l m   i s a p p r o x i m a t e l y
 1 . 1 2 8 T o u s e t h i s m e t h o d ,  t h e   l i g h t  l e v e l o f  t h e
 h r g h l i g h t si s f  i r s t d e t e r m i n e d , a n d  t h i s E V v a l u e
 t a k e n a s t h e u p p e r e x p o s u r e  l i m i t  B y d o i n g  t h i s
 t h e o p t i m u m  e x p o s u r e w i l l b e b a s e d o n  t h e   l i g h t
 areas

The light levelread at the highlightsis set on the      E X P O S U RFEO RS P E C I A EL F F E C T S
exposurecalculatorby index 10 of the IRE Scale.     H i g h l i g h t m e t e r i n g   i s a l s o a c o n v e n i e n t m e a n s o f
W i t h c o l o r f i l m , o n l y t h o s es h a d o w sw i t h a  l i g h t         achieving an underexposed, low-key effect which
levelreadingfalling to the right of index 1 of the                      i s d e s i r a b l e w h e n c r e a t i n g a n o c t u r n a l a t m o s p h e r e
IRE scale(black level)will be reproduced.Areas                      i n a da yti me shot.
w i t h a  l i g h tv a l u ef a l l i n gb e l o w i n d e x 1 w i l l             To achieve this effect, read the  light level of the
appearas unrelievedshadow.                             h i g h l i g h t s , a n d s e t t h i s n u m b e r o n  t h e e x p o s u r e
Therefore,when the light levelof the highlights          c a l c u l a t o r b y o n e o f  t h e   l R E   i n d e x e s c h o s e n  i n
has beenset on index 10, if important shadow         accordance with  the degree of density desired in
detail has insufficient light to bring it above              the resu lti ng photograph.
i n d e x 1 , i t w i l l h a v et o b e g i v e na d d i t i o n a l            F o r e x a m p l e ,i f t h e  l i g h t l e v e lo f  t h e h i g h l i g h t si s
i l l u m i n a t i o nu n t i l i t s l i g h t l e v e lr e a d i n gd o e s          E V 1 6 , a n d t h i s v a l u ei s s e t o n t h e e x p o s u r e
exceedthis mark.                                    calculatorby the standardindex, the highlights
                                                                will be reproducedin a gray tone as if they were
                                                    a standard 18% ref lectivesurface.

                           www.butkus.us

SF{l\ilff\,VffiFAUlNfiIVIFT[-{0D
T h e  r e v e r s e o f  t h e h i g h l i g h t  r e a d i n g m e t h o d ,  t h i s
m e t h o d g i v e s a n o p t i m u m  e x p o s u r e b a s e d o n  t h e
shadow areas. Shadow read ing is em ployed   f or
b r i n g i n g o u t d e t a i l o f p e r s o n s p i r o t o g r a p h e d w i t h
b a c k l i g h t i n g , a n d  f o r  f u l l y  r e p r o d u c i n g s h a d o w
d e t a i l  i n p i c t u r e s t a k e n a t n i g h t .
W h e n o r d i n a r y   l i g h t m e t e r s a r e u s e d t o s e t
e x p o s u r e f o r e v e n i n g o r n i g h t t i m e s c e n e s w h i c h
a r e n o t b r i g h t l y   i l l u m i n a t e d b y n e o n o r o t h e r
 l i g h t i n g , t h e  r e s u l t i n g p h o t o g r a p h h a s t h e s a m e
a p p e a r a n c e a s a d a y t i m e s c e n e . B y u s i n g t h e
s p o t m e t e r a n d  t h e s h a d o w  r e a d i n g m e t h o d ,
exposures can be set to give evening scenes an
 " E v e n i n g - l o o k " a n d n i g h t t i m e s c e n e s a
 " N  i g h t t i m e - l o o k . "

R e a d t h e   l i g h t v a l u e s o f  t h e s h a d o w a r e a s i t   i s
d e s i r e d t o  r e p r o d u c e , a n d s e t t h i s   l i g h t   l e v e l o n
t h e e x p o s u r e c a l c u l a t o r b y   I R E   i n d e x   i  .
 I n t h i s c a s e , a r e a s o f    l i g h t v a l u e f a l l i n g b e t w e e n
 i n d e x e s 1 a n d 1 0 o n  t h e  I R E S c a l e w i l l b e
r e p r o d u c i b l e o n c o l o r  f  i l m . A r e a s o f   l i g h t v a l u e
f a l l i n g a b o v e  i n d e x 1 0 w  i l l b e w a s h e d o u t .
C o n s e q u e n t l y , i f   i m p o r t a n t h i g h l i g h t d e t a i l h a s
a  l i g h t  l e v e l f a l l i n g a b o v e  i n d e x 1 0 w h e n s h a d o w
 l i g h t  l e v e l h a s b e e n s e t a c c o r d i n g  t o   i n d e x 1 ,  i t
w i  l l b e n e c . e s s a r yt o  r e d u c e  i l l u m i n a t i o n o f
t h e h i g h l i g h t a r e a , o r  t o  r e d u c e t h e  r e f l e c t i v i t y
o f  t h e h i g h l i g h t , u n t i l   i t s  l i g h t  l e v e l f a l l s
o n o r b e l o w   i n d e x 1 0 .

                             www.butkus.us

L I G H TR E F L E C T I V IOTFY7 C O L O R S       D O N ' TB EM I S G U I D EB DY C O L O R S
                                           You should be careful about colors when using
                         Reflectivity(%l  Index No.      the Digital Spotmeter. lf exposureis set strictly
Red (bright red)      1 5 - 2 1            6             on the basisof a light level readingtaken from                                                    a color area,there is a good possibilitythat
Orange             3 5 - 4 5        6 - 7           the exposurewill be incorrect.This is because
Y e l l o w ( d a r ky e l l o w )  6 5 - 7 5      B                reflectivity is different for different colors.
                                             The ref lectivity of yellow is lower than that ofGreen (dark leaf-green)1 8 - 2 6     StandardI ndex                                                     white, but yellow has the highestref lectivity of
B l u e               1 5 - 2 1        5                  all the colors. lndigo and purple have the lowest
I n d i g o                   o -      t z       2 - 3             reflectivity.Consequently,if a light levelvalue
                                                   taken from a reading of a yellow area is set on theP u r p l e              6 -  1 2       2 - 3                                                exposure calculator according to the standard
                                                     index, the photographwill be somewhat under-
                                                 exposed.To prevent this, set light readingstaken
                                                 from the variouscolors accordingto the
                                                correspondingindex number listed in the table
                                               on the left.

C L O S E - RU EP A D I N G
Becauseof the extremely narrow 1" measuringangle,
light meteringof a point should be possiblewith
the PentaxSpotmeterV without approaching
the subject.Consequently,there is no need to
bring things into sharpfocus as with a camera.
Nevertheless,if  it should be necessaryto come
extremely close to the subject in order to measure
a very small point, the fact that the objectivelens
is of fixed focus might make viewing diff icult. In
such a case,unscrewingthe adjustableeyepiece
to the limit of its travel will make viewing a little
easier.lt will be noticed, however.that the digital
display is now out of focus, and readjustment
may be necessaryto read the value indicated.

S E L E C T I NF GI L T E R S                 U S EI N S E L E C T I NC GO L O R S
When photographingcolored objectswith black       The age of color has arrived in television
and white f ilm, it is necessaryto take into account      broadcasting,but while almost all moviesnow
the ref lectivitv of each of the colors. While contrast     televisedare in color, they are viewed on black
betweenadjacent colors may appear good to          and white televisionsetsas well as color. For this
the eye, if their ref lectivitiesare nearly the same,      reasonit will not do to make moviesf or television
the contrastin the resulting black and white           broadcastingwhich are attractivein color, but
photographwill be disappointing.As is well known,     drab in black and white.
the use of color f ilterscan improve contrast in         Thus, it is necessaryto considercolor distribution
casessuch as the above,but it is diff icult to judge       a n d c o m p o s i t i o na, s w e l l a s s i m p l el i g h t v a l u e s ,
which f ilter to use.                            when f ilming for color television.
By mounting diff erent f ilters in f ront of the                      lf light valuesare determinedwith a Pentax Digital
objective lens of the Pentax Spotmeter and            Spotmeter,not only willthe brightnesscontrast
comparingthe readingstaken of the various          be known, but the proper choice of colors can be
coloredareaswith each f ilter, it will be easy to         decidedas well. This principle is being utilized
determinewhich one providesthe best contrast       now in the creationof displaysand designsof
f o r b l a c ka n d w h i t e f i l m .            www.butkus.usa l l t y p e s .

TRIPODMOUNTING

1 .   l f t h e D i g i t a lS p o t m e t e rc a n n o t b e h e l d s t e a d i l y
enoughby hand, it can be mounted on a tripod
and usedf rom there.
2. As shown in the photograph,the D igitaI
Spotmeter is equ ipped with a f r ipod Socket for
mounting on any standardtripod. The Spotmeter
can be mounted on the tripod with the wrist
strap in place.





                           www.butkus.us

l  ECAUTIONSLPR

 1.  lf the MeteringButton is squeezedwhen the          3. When taking a readingf rom a dimly-lit subject
 lenscap coversthe ObjectiveLens,the digital            (e.9.EV 3 or below) and then immediately
d i s p l a yw i l l  i n d i c a t e" O "  ( z e r o ) ,b u t  i f a s m a l l         changingto a bright subject (e.9.EV 6 or above),
a m o u n t o f  l i g h t e n t e r st h e l e n s ,t h e d i g i t a l d i s p l a y      the resoonseof the Silicon Photo Diode will be
wi ll indicateO o or O o o. However,since the           instantaneousand a correct readingwill be
exposuremeasurementrangeof the Digital            obtained.On the other hand, when f irst removing
Spotmeter is EV 1 - 20 (100 ASA), do not use         the lenscap and commencingthe f irst exposure
measurementswhich fall below EV 1.                  reading,a few secondsmay be necessarybefore
2. Ref lectionsnear the vicinity of the Silicon           receivingthe correct exposure measurement.
Photo Diode have been greatly reduceddue to
the new designincorporatedinto Spotmeter V
and the Digital Spotmeter.Becauseof their
exceptionalefficiency,the readingsyou obtain
may be slightly lower than those of other
spotmeters.Therefore, if you detect such
a difference, do not be concerned.



26