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Spectra Professional II User manual
User manual for Spectra Professional II. 61 pages in English. Read the original PDF, download or print a copy without registration.
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- Brand
- Spectra
- Model / document
- Spectra Professional II
- Document type
- User manual
- Language
- English
- Pages
- 61
- File size
- 3.4 MB
- Category
- Film cameras
- Document date
- Not specified in catalog
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Page 2 · Read text
FOREWORD
'You now own the Spectra*Professionalll* - one of the world's most odvonced,Congratulations!
most sensitiveexposuremeters.The meter is direct-readingin f/stopsfor both incident-and reflected-
light measurement,and coversa sensitivityrangeof 10 million to one.The Professionalll features
siliconcellsand solid-stateintegratedcircuitryfor stabilityand fast response.
This manualhas beenpreparedto enableyou to enjoy optimum performancefrom your new meter.
The informationset forth in this manualwill serveyou overthe years,and the few minutesyou invest
now to acquaintyourselfwith its contentswill reap rewardsfor you throughoutthe life of your
instrument.
CAUTIONNOTES
1) Your Spectra@exposuremeter is a precisioninstrumentand shouldbe handledas such.Do not
drop the meter or sub.iectit to excessiveshock,vibrationor temperatureextremes!Store it in its
carryingcaseor shippingcartonwhen not in use.
2) The instrumentis shippedwith the battery removedto preventpossibledamagecausedby a
leakingbattery.(lnstructionsfor installingthe battery aregivenin Section5.2 of this Manual.)When
instafling the battery, check that it is installed as indicoted on the polority label inside the battery
compartment.lf the instrumentis to be storedfor a long time, removethe battery.
3) Do not attempt to check or adjust the meter zero before readingSection 5.4 "Meter Zero
Adjustment".
*"Spectro" and "Professional" ore trodemorks of the Photo Reseorch Division of Kollmorgen Corporotion. (See
Section 6,5 for a complete list of trodemarks.)View original page 2Page 4 · Read text
Battery Tert
B u t t o n
Meter Zero Adjuster
Battery Compartment Cover Battery CompartmentView original page 4Page 11 · Read text
1.0 OPERATINGINSTRUCTIONS:EXPOSUREDETERMINATION
This Sectionoutlinesthe correctoperatingprocedurefor use of the SpectraProfessionalll exposure
meterfor determiningexposure.The readeris referredto the illustrationson the inside-frontcoverfor
partsidentification.
1.1 CONDENSEDOPERATINGINSTRUC. TIME window (or in the CINE window, for
TIONS motion picturecameras).
The following is a brief outline of operating 3) Preselectthe light-levelrange (Hl, MED
instructions.For additional information, see or LO)
Section1.2 through1.5. Usingonly the raisedRangeSelectorActuator,
turn the computeruntil the appropriateword -
Hl, MED or LO lines up with the Range
1.1.1 Settingthe Computer IndicatorArrow (at the bottomof the computer).
1) Set the Film Speed
NOTE: Use the Hl rangefor outdoorsand highLift the Film SpeedSettingTab (seephoto "A"
light levels,MED for indoors,and LOat left). Turn the outer dial of the computer(see
for low-light-levelphotography.photo "B") until the FILM SPEED Indicator
points to the ASA speed of the film you are '1."1.2 Makingthe Light Readingusing.Then push the Tab down (seephoto "C")
to lock-inthe setting. For incident light measurements,proceed as
follows: 2) Set the shutter speed
Turn the outer dial of the computeruntil the 1) From the subjectposition, point the Photo-
shutter speed you desire appearsin the EXP sphere@towards the comero.View original page 11Page 12 · Read text
I NCIDENT-LIGHTMEASUREMENT REFLECTED-LIGHTMEASUREMENT
EQUALtLLUMtNATI0N
CI
CAMTRA SUBJECI
N O R M A L L I G H T
2) Press the On/Off button, as indicared in
Section 1 .1 .3, to take the reading. part of the subject, being certainto includeboth
h ighI ight and shadowareas.
'l .'l .3 Readingthe Exposure
For reflected-light measurements, proceed as
follows: 1 ) Squeeze the On/Off button and hold it
u ntil the meter pointer comes to rest; then 1 ) Remove the Photosphere by pressing in- releasethe b u tto n slowIy.w ard s o n t h e b la ck knurled ring and turning it
approximately 60" counterclockwise. (Store the NOTE: lf the meterpointercomesto restin thePhotospherefor safekeeping.) red portions of the meter scale,it is
2) Rotate the swivel head so that the L ight advisableto chonge the RangeSelector
Sensorfaces th e back of the meter. and repeot the light reading. lf the meter
3) Point the Sensor towards the important pointer is in the red portionat the rightView original page 12Page 15 · Read text
'1.2.3 Setting the Light-LevelRange falls in the red portion of the meter scale,it is
advisableto reset the range and take anotherThere are 3light-level range settingson the
computer.The Hl (high) rangeis for high light light reading.lf the meter pointer is in the red
portion at the right side of the scale,move thelevels,commonly encounteredoutdoors; the
MED (medium)rangeis for intermediatelight Range Selector one range counterclockwise.lf
levels,generallyfound indoors,while the LO the pointer is at the left side of the scale,move
(low) rangeis for very low light levels.There is one rangeclockwise.
some overlapbetweenranges,but for optimum It should be noted that resettingthe Range
accuraeyit is best to be on a rangewhere the Selectorreleasesthe previousreading,and the
meter pointer falls in the center of the meter meter pointerwill drop to zero.(Thisis a feature
scale. designedto preventerroneousexposurereadings
causedby changingrangeswithout taking a new
To set the range, place your thumb over the light reading.)Always take a new light reading
raisedRangeSelectorActuatorand push or pull after changing ranges!
the raised actuator until the entire computer
beginsto turn. (Do not changerangesby forcing 1.3 MAKING INCIDENT-LIGHTREAD-the Range lndicator Tabsl) Continue turning INGSuntil the desiredRangeIndicatorTab (Hl, MED
or LO) lines up directly opposite the Range 1.3.1 When(andWhenNot) to MakeIncident-
IndicatorArrow at the bottom of the computer. Light Readings
Do not leavethe computerbetweenranges,as
lncident-lightreadingsare made by measuringthe meter will not operate unless the Range
the light fallingon the subiect.They are simpleIndicatorArrow is directlyoppositeone of three
and quick to make,relativelyfoolproof, and areRangelndicatorTabs!
the preferredmethodof determiningexposurein
After makinga light reading,if the meterpointer almostall conventionalphotographicsituations.View original page 15Page 16 · Read text
The key to the successof the incident-light method is the largehemisphericalPhotosphere@, which simulatesa th ree-dimensionalsubject.The Photosphere"integrates"or averagesthe effect of all of the different lightson the subiect(see illustration),and weighsthem proportionallyto their effecton the exposure. Certainsituationsin which incident-lightreadings shou ld n ot be u sedd irectly are: 1) Whenthe subjectis inaccessible(to that it is physicallyimpossibleto hold the exposure meter near the subject)and the lightingis non- uniform (sothat the lightingon the subjectis not the sameas the generallighting). 2) When the importantpart of the sceneto be photographedis unusually light (suchas a snow- coveredlandscape) , or u n u sually dork (such as a blackcat). The inaccessible-subjectsituationwould best be handled by reflected-lightmeasurement(see Section1 .4),whilethe lightldark subjectsituation would best be meteredby eitherthe reflectedor the " h ighlight-shadowaverage" method (see Sections1.4 and 4.2). The light l dark subiectView original page 16
Page 17 · Read text
situation can also be read by incident_light 2) Hold the meter at the principalpoint of
measurementif operator judgement is used; interest of the subject with the photosphere
simply decreosethe meter-indicatedexposureby pointing directly towards the camero (see illus_
approximately% of an f lstop for unusually,light tration below).lf it is not possibleto get closeto
subjects,or increosethe exposureby approxi_ the subject, bur the lighting is uniform (for
mately % stop for unusually dark subjects.For example,outdoorsunder open sky), hold the
very light (or dark) subjecrswhich do not include meterparallelto the subjectwiththe photosphere
a significantamount of fleshtone,increase(or pointingtowardsthe camera.
decrease)the exposureby 1 full f/stop. INCIDENT-LIGHTMEASUREMENT
Specificsuggestionsfor handlingspecialsubjects
aregivenin Section4.3.
EQUATlLLUMlNArlotl
1.3.2 tncident-lightMeasuringprocedure !..*.1.i,.. ''i.@:t''
^'i.,r.j'.r..
.l \lncident-light.measurements,using the pro_ rtt ta
t tfessionalll, aremadeasfollows: " . 'ao 1) Check rhar rhe photosphere(the white I. hhemisphere)is in placeoverthe f isht Sensor. h- | l/nNOTE: To install rhe photosphere,align the 3 /l\ n
CAMERA SUEJECT bayonets (on the back of thJ photo_
N O R M A L L I G H T U N E V E NL I G H T sphere)into the meter,sbayonetmount.
Then pressinwardsfirmly on the black
knurled ring a.ndturn it approximately
60' clockwise(untilthe bayonets,,clicki, NOTE: lf necessary,rotate the swivelhead so
into place). that the Photospherewill not pick upView original page 17Page 18 · Read text
,1 any reflections or shadows from the .4 MAKING REFLECTED.LIGHT READ.
p h otograph e r. I NGS
1.4.1 Wherr (and When l.lot) to Make Reflected- 3) Press the On/Off button and make the
Light Readingsrea d in g(a s in d ica t edin Section1.5).
Reflected-lightreadingsare made by measuring
R O T A T E S W I V E L H E A D T O A V O I D R E F L E C T I O N S the light reflected back from the subiect towards
O R S H A D O W S F R O M T H E P H O T O G R A P H E R the camera.
The reflected light method has the theoreticol
advantagethat it is possibleto determineoptimum
exposure for all given subjects, since the method
is based on the ligh t reflected from the actuol
subject. In the situation described in Section
1.3.1, the snow-coveredlandscapewould reflect
more light and the meter wou ld call for less
exposure; the black cat would reflect less light
and the meter wou ld call for more exposure.
Unfortunately, the theoretical advantageof the
ref lected light method is often lost in practice
because of the need for the photographer to
decide what portion of the subject should be
meosured. For example, if the photographer
includestoo much bright sky or white background
in his reflected-light measurement, the meter
reading will be too high and the foregroundView original page 18Page 19 · Read text
subiectwill be underexposed;if he includestoo The large-areameasuringprocedureis as follows:
much shadow area in the measurement,the
meter readingwill be too low and the photo- 1) Remove the Photosphere by pressing
graph will be overexposed.Since successof the inwardson the black knurledring and turning
it approximately 60"counterclockwise.Store thereflected-lightmethod is highly dependentupon Photospherein the carryingcaseor other pro-the photographer'sjudgementand carein making tected location.
the measurement,it is generallyinferior to the
incidentlight methodwheneverthe photographer 2) Rotate the swivel head so that the Light is in a rushto take a reading. Sensor^ facesthe bock of the meter.
One specificsituationin which the conventional
reflected-lightreadingwill be erroneousis in 3) From the cameraposition,point the Light
caseswhere the subject is small and is either Sensor towords the important part of the subject.
much lighter or darker than the background, Rememberthat the Reflected-LightSensorsees
light over a 42" field, similar to your cameraand it is not possibleto get closeenoughto the equippedwith a normal lens; thereforeif thesubjectto takea small-areareflected-lightreading. sceneis nonuniform,you should move in close
Unless the photographerhas the Spectra 1" enough to the subject to exclude extraneous
PhotoSpotaccessory,he is betteroff to makean background (but stay far enough away to include
incident-lightreadingin tirissituation. both important highlightand shadowareas).Be
carefulnot to castany shadowsor reflectionson'1.4.2 Reflected-LightMeasuringProcedure the subject.Also be carefulnot to tip the Sensor
upwards,as this may result in including tooReflected-lightmeasurementscan be madeeither much brightsky in the reading(andconsequentialby the simple "large-area"techniquedescribed erroneousexposure).lf the subjectis back-lit,below, or by the more advanced(and compli- either turn off the back-lightsor move close
cated) "smoll-qreo" techniques described in enoughto the subjectso that the meterdoesnot
Section4.2. measurethe back-lights.View original page 19Page 20 · Read text
4) Pressthe On/Off button and make the
reading(asindicatedin Section1 .5).
n|.4.3 Usingthe 1'PhotoSpotAcessory
The 1" PhotoSpotaccessory(seeSection3.1) can
be usedfor exposuredeterminationby eitherthe
small-areareflected-lighttechniquesdescribedin
Section 4.2, or as fo I lows:
1) Remove the Photosphereby pressingin-
wardson the black knurledring and turning it
approximately 60' counterclockwise.(Store the
Photospherefor safekeeping.)
2) | nstall the 1" PhotoSpot(seeinstructions
packedin the PhotoSpotcarton).
3) Set the distancescaleon the PhotoSpotto
correspondto the approximatedistancebetween
you and the subject.
4) Standingat the cameraposition,point the
PhotoSpotlens towards the subjectand look
throughthe PhotoSpot'sviewfinder.(lf necessary,
turn the viewfindereyepieceso that the imageof
both the subjectand the bright 1" circle are as
sharp as possible.)tfren center the critical area
(for example,the subject'sface) in the 1" circle
in the viewfinder,being certainto includeboth
importanthighlightand shadowareas.
1 0View original page 20Page 21 · Read text
5) Pressthe OnlOff button on the meterand 2) Read the f/stop indicated by rhe posirion
makethe reading,as indicatedin Section1.5. of the meter pointer.
NOTE: View the meter from directly over the
pointer to eliminate possible reading
error. The reading will be correct when
the meter pointer appears stroight and
1 . 5 R E A D I N G T H E E X P O S U R E of minimum th ickness.
After the meter has been positionedto make the
light reading, as describedin either Section I .3
or 1 .4, the exposure readingis made as follows:
1) Pressthe On/Off button and hold it until
the meter pointer comes to rest; then releasethe
button slowly.
NOTE : lf the meter pointer comesto rest in the
red portion at either end of the meter
scale, it is advisable to change the Range
Selector and repeat the light reoding. lf
the meter pointer is in the red portion
at the right side of the scale,move the
Range Selector one range counterclock-
wise. lf the pointer is at the left side of
the scale, move one range clockwise.
Then repeatthe light reading.
1 1View original page 21Page 22 · Read text
3) lf you would prefer to use a different shutter speed! Read both the new f/stop and the
, f f stop,simplyturn the outerdial of the computer new shutter speed when you have finished
until the preferredf/stop linesup with the meter turningthe outer dial.
pointer.Note that this operationalsochangesthe
1 2View original page 22Page 25 · Read text
2 . O M I S C E L L A N E O U MS E A S U R E M E NT S
This sectiondescribesthe correctoperatingprocedurefor makingvariousspecialmeasurements- such
as llluminance(foot-candleor dekalux),LightingContrastand SubiectContrastmeasurements.
Other specialmeasurements,which requirevariousSpectraSystemAccessories,areoutlinedin Section3.
2.1 TLLUMTNANCE(FOOTCANDLEOR 2\ | nstall the Photodisk@ (ttre flot wh ite
D E K A L U X ) M E A S U R E M E N T S diffuser) over the Light Sensor:pressinwards
firm fy and tu rn clockwiseto secure it.
llluminonce is the scientific name for the measure-
m e n t o f in cid e n tlig h t . The units of measurement
f o r i l l umin a n ceis co mmonly the "footcandle" in
t he U n it e d S t a t e s,a n d the "lux" or "dekalux"
(l u x t i me s 1 0 ) in in t e r nationaluse.
Your Spectra meter can be used to read d irectly
in foot-candles or dekalux, according to the
f ol l o w i n g p ro ce d u re :
1 ) Re mo ve t h e P h otosphere@(hemispherical
w h i t e dif f u se r)b y g rippingthe black knurledring,
p re s s in gin wa rd s f irmly and turning it approxi-
mately 60" counterclockwise. (Store it in the
carryingcaseor other protected location.)
1 5View original page 25Page 26 · Read text
3) Preselectthe light-levelrange(Hl , M E D or b) Without changing the Film SPeed
LO) asfollows: setting,simply rotate the outer dial until the
footcandlescalevalue indicatedbelow lines up Hl High light levels(40 to 50,000footcandles with silverreferencemark on the meterscale(see
or dekalux) photo at left) :
MED Mediumlevels(0.4 to 1,000footcandles
or dekalux) Light-Level Align FootcandleValueto
Range ReferenceMark on Meter Scale LO Very low levels(0.004to 10 footcandles
H t 1 0 0 or dekalux)
M E D 1
4\ Programthe computerto readllluminance LO .01
by eitherof the followingmethods:
a) Set the Film Speeddial (asdescribedin NOTE: Once set as indicated,the outer dial
Section 1.1.1) to align the red "FC" (Foot- shouldnot be moved until the illumi-
Candle) mark with the F I LM SPEE D pointer. nancemeasurementis finished.
Then rotate the outer dial of the computer
until the other red " FC" mark appearsin the 5) Hold the meter with the Photodiskin the
CINE window. plane in which it is desiredto measurethe
illuminance.
6) Pressthe On/Off button and hold it until
the meter pointercomesto rest;then releasethe R E F E R E N C E
M A R K buttonslowly.
NOTE: lf the meterpointercomesto restin the
red portion at either end of the meter
1 6View original page 26Page 27 · Read text
, scale,it is advisableto changethe Range
Selector and repeat the light reading. lf NOTE: The phoro below will help you to
the meter pointer is in the red portion interpret u nmarked valueson the
at the right sideof the scale,move the meterscale.
RangeSelectorone rangecounterclock_
wise. lf the pointer is at the left sideof
the scale,move one rangeclockwise.Be
,,{vrafulnot to disturbthe settingof the
outerdial whenchangingranges.
7) Observethe positionof the meter pointer
relativeto the computer.This is the illuminance .--,J3333value of the incident light, expressed in FOOT_ ': '"t!Z-4O,OootCANDLES. The reading is so.ooo also approximately
equalto the valuein DEKALUX (lux times10), U N M A R K E D V A L U E S O N
since1 foot-candleequals1.0j6 dekalux. F O O T C A N D L E S / D E K A L U X S C A L E
1 7View original page 27Page 28 · Read text
2.2 LIGHTING CONTRAST 4) Point the Photodiskat the key light source
and take a readingof the unshadedkey light.LightingContrast is defined as the rotio of the
illuminationproducedby the key light plusfill 5) Without disturbingthe computer,observe
lightto that producedby the fill light alone. the position of the meter pointer on the foot-
candlescale.This valueis the key-to-fillratio ofWhile the exact valueof LightingContrastfor a the lightingset-up.particularsceneis a matterof artisticchoice,the
following ronge of values are commonly NOTE: lf it is desiredto modify the lighting
suggested: ratio, changethe lightsand repeatSteps
2 through5. After the lightingratio has C o l o rF i l m s : 1 . 5 : 1t o 5 : 1 beenoptimized,replacethe Photosphere
Black& WhiteFilms: 2:1 to 16:1 and determine the exposure by the
incident-lightmethod(seeSection1.1).LightingContrastis measuredasfollows:
2.3 SUBfECT CONTRAST(BRTGHTNESS
1 ) Preparethe meter for the measurementof RATrO)illuminanceas describedin Section2.1, Steps1
through3. Subject Contrast is different from Lighting
Contrastin that it is a measurementof the light 2) Hold the meter in the subjectplane,with ratio reflected from the actual subfect.the Photodisk pointed towards the camera
position.Use your hand to shadethe Photodisk Subject Contrast, sometimescalled Brightness
from the direct rays of the key light, and take a Ratio, is definedas the ratio of the brightnessof
readingof the fill light. the brightesthighlight to that of the darkest
shadowin which detailis desired.For optimum 3) Turn the outer dial of the computerso that tone reproductionthis ratio should be on thethe I foot-candlemark is alignedwith the meter order of 4:1 to 32:1 for color films and32:1 topointer. 128:1for black-andwhite films.View original page 28Page 31 · Read text
3.0 SPECTRA @ SYSTEM ACCESSORIES
A completeline of precision-madcaccessoriesareavailableto expandthe useof your Spectracxposure
meter.Thescincludethe following:
r' 1) Spectra1'PhotoSpot (SpotmetcrAttachment)
2) SpcctraFlexi-Probe'" (FlcxibleFibcrOpticsprobe)
3) SpectraPhotoreaderruProbc
4) SpectraSpot-RcaderrM(Enlargingand DensirometryAttachment)
5) SpectraMicroscopeAdaptcr
Theseaccessoricsarc bricfly dcscribedon the following pages.Completeoperatinginstructionsare
packedwith thc individualacccssory.
21View original page 31Page 32 · Read text
3.1 SPECTRA@1. PHOTOSPOT
The Spectra 1" PhotoSpot is a unique optical accessorythat convertsyour exposuremeter into a
high-sensitivity1'Spotmeterfor narrow-anglereflected-lightmeasurements. Use of the PhotoSpotwill enableyou to make accuratereflected-lightreadingsof distant subiects- II
particularlyusefulwith telephotolensesand for inaccessiblesubiectslike storewindows,theatrestages,
animalsand wildlife. lt is also valuablefor photographingsmall sublectsin close-upphotography,for
making accurateSublect Contrastor BrightnessRatio measurements,and for making "zone system"
measurements.
The PhotoSpot featuresa bright, wide-field,life-
size viewing system with a focusing eyepiece.A
sharp reticle in the eyepieceaccuratelydefines
the 1" measuringfield. Parallaxcorrectionis pro-
vided for h ighest accuracy for all d istancesfrom 1 8 i n c h e s ( 0 . 5 m e t e r ) t o i n f i n i t y . A u n i q u e I
electro-opticalsystem makes the exposuremeter I
direct-readingwhen the PhotoSpotis in place.
lIner
spectro
l o l
l- photospot
22View original page 32Page 33 · Read text
3.2 SPECTRA@ FLEXI-PROBE
The SpectraFlexi-Probeis a flexiblefiber-opticsprobe which enablesyou to make small-arealight
readingsin nearlyinaccessiblelocations.Typicalapplicationsincludeground-glassexposurereadings,
uniformity measurements,brightnessmeasurementsin physicallyrestrictedlocations,and small-areaI
densitomerry(on a light table).
The Flexi-Probeconsistsof a high-quality24-inch(0.6 m) fiber-opticsprobeand a mountingadaptor.
Thc measuringdiameterof the probels 0.125-inches(3 mm),enablingverysmallarcasto be probed.
the
spoctro
f lexr-probeView original page 33Page 34 · Read text
3.3 SPECTRA@PHOTOREADERPROBE
The Spectra PhotoReaderProbe is an accessorydesignedto enableyour exposuremeter to make
small-areameasurementsfrom the cameragroundglass,focusingscreenor similarrestrictedlocations.
The PhotoReaderProbeconsistsof a rigid opticalcollectorwhich is f -inch(25 mm) long.The measuring
areais}.22-inches(5.5 mm) in diameter.
the
spoctro
photorooder probeView original page 34From the M. Butkus archive. Original publisher and archive notices are retained.
Check the model and edition against your equipment.
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