Afreee-Booklet,withthecomplimentsofGrahamHoughton

UNDERSTANDING

EXPOSURE

Allyouneedtoknowtotakeperfectimageswithyourcamera.

GrahamHoughton

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TableofContents

Introduction:..............................................................................................3

WhatIsExposure?.....................................................................................5

TheElementsofExposure.......................................................................12

ControllingExposure:Aperture...............................................................14

ControllingExposure:ShutterSpeed......................................................16

ControllingExposure:ISO........................................................................18

NoiseintheDigitalCamera:....................................................................18

WhiteBalance:.........................................................................................20

ExposureandMetering:..........................................................................23

MeteringModes:.....................................................................................25

TrickyExposureSituations:......................................................................26

DynamicRange:.......................................................................................27

SomeThoughtsonControllingDynamicRange:.....................................30

Conclusions:.............................................................................................32

GlossaryofPhotographicTerms:............................................................32

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Introduction:If you a new convert to the world of digital photography using more than a simple smartphone to capture your images you could be forgiven for thinking that setting the exposure is complex. One of the main reasons, I would argue, is that manufacturers have a vested interest in promoting this as a highly complex procedure that only their camera metering systems can help you with! This would encompass even more sophisticated technologies such as different metering modes, auto exposure options, dynamic range optimisation and so on. This is not the case at all and you will become to understand that these automated and supposedly "intelligent" options are really hindrances when it comes to understanding how to get the correct exposure! The "problem" here is a very simple one. There are exposures that are clearly wrong - for example those which are grossly over or underexposed - sometimes to the extreme that the subject is no longer recognisable. I would argue that there is no "correct" exposure for any given subject/scene.

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Consider the numerous combinations of Aperture, Shutter Speed and ISO there are which would produce vastly different looking images as well as producing lighter or darker images. Consider this. Shooting by deliberately underexposing the image by 2 F-stops to create an intentional silhouette of your subject which is offset against a vibrant sunset is correct! So is over exposing your image by 2 F-stops if you are shooting a backlit subject to bring out the shadow detail! Both of the resulting images are both entirely different and technically correct! Correct being the extent by which your captured image matched your "mind’s eye" when you conceived this image. Our camera can't "see" the world that it is shooting - not at least in a meaningful way and it absolutely cannot make any creative decisions on its own as it just obeys a basic set of exposure algorithms programmed into the camera firmware. Let's face it, the camera is "best guessing" exposure! I've probably been a little cruel here - for if you are a novice photographer the fully automated iA or semi-automated modes can make all the difference between getting an image versus no image at all. So where is this debate going? Well it’s back to the statements I've made repeatedly when using Panasonic Bridge/ Travel Zooms and CSC's and that is forget anything to do with digital enhancements in the camera set up. So that means no I.Resolution, I.Dynamic and I.Zoom etc. Forget iA and iA+ modes and make the basic choice from "A" aperture priority when depth of field is the primary choice for the image or "S" when its necessary to use fast (or slow) shutters speeds to stop or create subject motion blur in the image. Set ISO to the native camera value which is usually 100 (200 in larger sensor cameras) and keep it there.

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If you are shooting for the best possible image set the mode dial to "A", turn your control dial to set an aperture of F4 and go out and take some great pictures. The only time you will need to over-ride the camera metering system is when there is a disproportionate ratio between the subject and background brightness's. Such scenes would include snow and beach scenes which always result in the camera under exposing your image. In time you will begin to "see" these scenes and automatically apply exposure compensation routinely.

WhatIsExposure?Inasimplisticstatementexposureisaboutmakingsuretherightamountoflightreachesthedigitalsensortoproduceanimagewhichlookscorrect!Therearenumerouswaystoachievethissoitisimportanttounderstandeachoftheelementswhichgovernthisexposure.Let’sbeginbylookingathowanimageiscapturedbythecamera.Insomeways,theimagecapturedbythecamerasensorisliketheimageseenusingourownvisionsystem,oureyesandbrain.Justasthephotonsoflight(thesearethefundamentalparticlesoflight;theyarebothparticlesandwavesandallowsfortheiruniquepropertieslikerefractionanddiffusion)striketheretinainoureyeandgenerateanelectricalsignal.Theretinaisathin,delicate,photosensitivetissuethatcontainsthespecial“photoreceptor”cellsthatconvertlightintoelectricalsignals.Theseelectricalsignalsareprocessedfurther,andthentravelfromtheretinaoftheeyetothebrainthroughtheopticnerve,abundleofaboutonemillionnervefibres.Inthecamerasystem,theretinaisreplacedbythephotosites,oftenreferredtoas“pixels”orpictureelements.Thephotonstrikingthesiliconatomsinthephotositereleaseelectronswhichareconverted

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intoanelectricchargewhichcanbeamplifiedandmeasuredinthecameraprocessingpipeline.Discountingtheelectronicsusedinthecamerasystemthemajordifferencebetweenthetwosystemsisinthefactthattheeyecanadapttochangingbrightnesslevels,andmoresignificantly,colourtemperaturechangesinrealtime.Thecamerasensorontheotherhandhasafixedsensitivityatthetimeoftheexposureanditisimportantthatthecamerasensorreceivesenoughphotonsduringthetimethattheshutterisopentoproduceanimagewhichisneithertoobrightortoodark.Inmanywayslikeourowneyescanbetemporarilyblindedbyintenselight,thephotositesinsensorhaveafinitestoragecapacity.Thiscapacitydependsupontheirphysicalsizewhichinturndependsupontheoverallsensorsizeandthepixeldensity.Thesmallerthephotositethequickerthatthesearefullysaturatedbythephotonsarrivingfromthelens.Oncethephotositehasbeenfilled,byelectronsreleasedbythephotonsstrikingit,itbecomessaturatedandnomatterhowmanymorephotonsstrikeittheycannotreleaseanymoreelectrons.Wecallthis“blowout”andaffectsthebrightestareasoftheimage.Aseachphotositehasanaccompanyingcolourfilter(physicallycoveringit)theseblowoutsmayoccurinany,orall,coloursthatarefullysaturated.Inthecameraimagingsystem,theoutputfromeachphotositeisananaloguedcvoltage.Thisvoltageisextremelysmallandneedsamplificationtobringittoasufficientlyhighenoughvaluetobe“digitised”inorderthatitcanbeprocessedmathematicallybytheimageprocessingsystem.

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TheamountofamplificationistiedintothesensitivitycontrolofthecamerawhichwerefertoasISO.Thereisalwayssomeamplificationneededtopresenttheanaloguetodigitalconverter(ADC)withavoltagelevelthatwilldeliverthefulldigitaloutputthattheADCcanprovide.Inourmodernsystems,theseADCshave14bitoutputscapableofgeneratingadigitalvaluethatcanbeoneof16384values.Ifthereisnovoltagepresent(blacklevel)thentheoutputfromtheADCis0.Ifthesensorisoutputtingwhitevalue,atasaturationpoint,theADCwilloutputavalueof16384.Thus,theimageismadeupfromeveryphotosite(pixel)analogueoutputdigitisedintoadigitalvalueintherangeof0to16384.Becauseoftheconstructionofthecolourfilterarray(normallyaBayermatrix)thedistributionofredtobluetogreenpixelsissuchthatthegreenphotositesaremorethantheredandtheblueones.Thisistoemulateourowneyessensitivitywhichispredominantlyinthegreenspectrum.

TheBayerColourFilterArrayandthede-mosaiccolourimage

Intoday’sworldofdigitalcameras,themostuniversaluseimagesensorspatternistheBayer(Mosaic)sensor.TheBayersensorisaU.S.patentregisteredin1976andthefirstdigitalcamerainventedbackin1975by

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EastmanKodakandStevenSassontousethissimilartechnology.Thisfilterpatternalternatesarowofredandgreenpixelswitharowofblueandgreenpixels.Eachpixelwilleitherhaveared,greenorbluefilterlayer(Seeimageabove).

TheBayersensorconsistof50%Green,25%Redand25%Bluepixels.Ordertoconverttherawinputintoafinalimage,thedigitalcamerausesspecialisedde-mosaicalgorithmstoconvertthesensordataintoRGBpixeldata.

Thecameracomputedthecolourusingseveraloverlapping,example2x2arrays.Thismethodsometimescanproduceanunrealisticlookingresult.

Themostcommonartefactisknownas“moiré”.

Moirépatternsareoftenanundesiredartefactinimagesproducedbyvariousdigitalcameraswhenshootingimageswithregularpatternslikebrickwallsetc.

However,toovercometheseartefactsdependonbothoftextureandsoftwareusingtodevelopthedigitalcameraRAWfile.

Oncetheimagedatahasbeen“re-constructed”itcanbereducedinnoise,youcontrollingtheamountofblurappliedtomaskeithernoiseinthecolour(chrominance)orbrightness(luminance)channels.ThisiswhereyoumakethemostsignificantimprovementoverincameraJPEGprocessedfiles.Theanaloguetodigitalconversioncanbeseenvisuallybylookingatthecamera“histogram”whichshowsthedistributionofpixelsfromblack(zerovalueontheXaxis)towhite(255valueontheXaxis).ThisisderivedfromthecameraprocessingsystemRAWsensordatawhichisusedtogeneratetheJPEGfile.Yetcameramanufacturers,havenotincorporatedasystemwhichcanshowtherealoutputvaluesfromthesensor.Assuchanycameraadjustments,whichareattributedtotheJPEGprocessingwillreflectinthedisplayedhistogram.Thingslikethephotostyle(andanyadjustmentstoitsparameters)andwhitebalancecanskewtheresults.

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Thehistogramisapictorialrepresentationofthenumberanddistributionofpixelsintheimage.Ontheleft-handsideofthegrapharethedark(shadowareas)andontherightthelight(highlightareas).Theheightofthebarsrepresentsthenumberofpixelsofthatvalue.Theshadowsrepresentadigitalvalueof0(zero)whilstthehighlightshaveadigitalvalueof255.Thus,eachcolourhasarangeof256discretebrightnessvalues.Animagewillhaveamaximumtonalrangeof256Red,256Greenand256Bluevaluesgiving16777216colourvaluescommonlyreferredtoas“truecolour”.Thedistributionpatternwillgiveanindicationontheexposure.Acorrectexposurewillhavebarsinthehighlightandshadowareaandapeakorclusterofbarsabouthalfwayrepresentingthemid-tones.Theplaybackhistogramismoreuseful,inmyopinionthantheon-screenhistogramavailableduringshootingasthisonlyshowsthetonalrangeoftheimage,nothowitwasrecorded.

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brightnesshistogramdisplayedduringshootingmode(ifenabledinCustomMenu(4/9)Thebrightnessvaluescanbeseeninthetwoexamplesofimagesshownabove.Thereisagroupingofbarsaroundthecentralareaofthegraphindicatingtheneutralgreybackgroundhasmanyrecordablepixelstheblacksoftheimage(value0)arevisibleaswellasthehighlightpixelswithavalueof255.Ifwelookbackamomentattheheartofthis,theanaloguetodigitalconverter,dependinguponthecameraitmaybeconstructedwith10,12or14bitsofprecision.Theprecisionwilldictatehowthefinalconversionwillappearintheimage.Toolowaconversionwillresultinbandingorcontouringespeciallyinareasofclosebrightnesssuchasinskiesorareasofsolidobjects.Itisthepurposeofthecamerasensitivitysystem,theISOcontrol,toensurethatthefullysaturatedsignalsappearinthehighestorderbitoftheADC.Thisiswherethemaximum,individualtonal,valuesappear.WithasimplepointandshootcameratheADCmaybe10bitsaDSLRontheotherhandmayhave14bitsofprecision.However,it’sworthrememberingthatduringtheconversiontoJPEGthisresultsinanimagewithjust8bitsor256discretelevelsofbrightnesspercolour.

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IfwelookatthatinmoredetailitmeansthatifwearetogetthemostpossibletonaldatainourimagerangingfromtheshadowstotheextremehighlightsourADCmustbepresentedwiththehighlightvoltagesetsothatithasthegreatesteffectontheimage.Onthehistogram,thismeansthatthehighlightsshouldbeasclosetotheright-handsideofthegraph,withoutclippingimportanthighlightdetail.Ifwecaptureanimagewherethehighlightsaremid-wayacrossourhistogramcurveitmeanstheimageisprobablyunderexposedandinsubsequentpostprocessingthewhitesmustbeincreasedbysomethinglikethe“Levels”adjustment,ormorecrudelywiththebrightnessandcontrastcontrolslider.

Ifyouhaveanimagewithahighlysaturatedcolour,liketheoneabove,itisusefultolookattheRGB&luminancehistogram.Ifwejustlookedattheblackandwhite(luminance)curveitappearsthatwemightbeunderexposingtheimage.However,lookattheredchannel.Ithaspixelbrightness’shardagainsttheright-handedgeindicatingthatsomeoftheredpixelsarelikelytobesaturatedandcontainnotonalinformation!Thistechniqueofplacingthehighlightsasclosetotheright-handedgeofthehistogramiscalled“ExposingtotheRight”orETTR.It’saprocessthatisbestsuitedtoshootingintheRAWformatasitallowsthefinalcontrastoftheimagetobesetasyouenvisionthesceneasyoushootit.

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Ifyouweretousethiswiththein-cameraJPEGprocessingoptionitislikelythatthehighlightswillhavebeencompressedandshownodetail.Thisdetailcannotberecoveredinsubsequentediting.

TheElementsofExposure

Lookingatthetraditional“exposuretriangle”thethreeelementsthatmakeupanexposurearetheAperture,theShutterSpeedandtheISO.Eachoftheseelementsaffectsthewayinwhichtheimageiscreated.Apertureaffectstheamountoflightreachingthesensor.Alargeapertureallowsmorelighttoenterthelensresultinginabrighterimage.However,itisprimarilyusedtodeterminetheamountofdepthoffieldintheimage.Asmallaperture(largeFnumberlikeF8)createsmoredepthoffieldthanalargerone(smallFnumberlikeF2.8).ShutterSpeedaffectsthedurationwhichlightfromthelensfallsonthesensorbutisprimarilyusedtodeterminetheamountofsubject

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motionblurintheimageeitherintentionallyorotherwise.Ashortshutterspeedarrestsanysubjectmotionwhereasalongershutterspeedcreatessomemotionblurinamovingsubject.ThefinalelementISOdoesn’tvarytheamountoflightreachingthesensorhoweveritsactionistobrightentheimagebyincreasingthegainoftheamplificationofthephotositesbeforebeingappliedtotheanaloguetodigitalconverter.Thethreeelementsworkinconjunctiontoprovidethecorrectexposure.Theexposurecanbecreatedbyanycombinationofthethreeelementssoinasensethereisnocorrectexposure,itisjustthewaythateachofthesettingswillinfluencethefinalappearanceoftheresultingimage.Ifyoumakeachangetooneofthethreeelementstokeeptheexposureconsistentyoumustmakeanoppositeandequaladjustmenttooneoftheothers(oracombinationofchangesintheothertwo).Forexample,iftheexistingexposurereads1/125sec,F5.6andISO100ifyouwantedmoredepthoffieldyoucouldgoforanaperturesettingofF8.TokeeptheexposurethesameyouwouldneedtoallowthecameratoexposethelightonthesensorforalongerperiodastheapertureopeningofF8issmallerthanF5.6thusreducingthelightintensity.Ifyouwantedtokeeptheshutterspeedthesamebecauseofsubjectmotionpossibilities,thenyouwouldneedtomakeacompensatingchangetotheISOtomakethecameramoresensitive.AchangefromISO100toISO200woulddothis.Thechoiceofwhichelementtochangeisobviouslydictatedbythesubjectbeingcapturedandtheneedsofthatimagewhenprocessed.

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ControllingExposure:ApertureAsweknowtheapertureistheholeinsidethelenswhichlimitstheintensityoflightallowedtoreachthesensor.Thus,alargerapertureallowsmorelighttoreachthesensorandasmalleroneobviouslyreducesit.

Asyoucanseetheaperturesizeisdenotedbya“F”numberandthisisamathematicalratioofthediameteroftheapertureandthefocallengthofthelens.Forexample,ifalenshadafocallengthof50mmandtheaperturediameterwas25mmtheF-stopwouldbe50/25=F2.ThatiswhyF4isalwaysthesameamountoflightirrespectiveofhowlargeorsmallalensisorhowlongorshortitsfocallengthis.Itisthisfactthatallowsustouselensesfromonecameramounttobeusedonothers–ifanadaptorisavailabletogetthefocuspointatinfinitytobeinfocusatthesensorplain.Thereferencetothe“F”numbersisbaseduponaseriesofnumbersonalog(2)scalenormallybeginningwithF1.0,then1.1,1.4,2.0,2.8,4.0,5.6,8,11,16andF22.Eachstepdoublesorhalvestheamountoflightpassedthroughthelens.

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Theprincipalreasonforusinganapertureisoneofbeingabletocontrolthedepthoffieldrecordedintheimage.

Inalandscapeshot,forexample,younormallywanteverythingfromtheforegroundtoinfinityinsharpfocussoweselectawide-anglelenssettingandasmallaperture.ItisworthrememberingthatwithasmallsensorcamerathecropfactorwillgiveextensivedepthoffieldsoevenanapertureofF4givestheequivalentofF22onafullframecamera.ChoosingasmalleraperturelikeF8doesn’timproveonthedepthoffieldandstartstosoftentheimagethroughdiffractionoccurringbecauseofthesmallaperturediameter.Focussingatadistanceof1/3ofthewayintothesceneusuallysetsthefocuspointatthehyperfocalfocusdistancewhichensuresthelenscapturesthemaximumdepthoffieldatthatapertureandfocallength.

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Theotherfeatureofalargeapertureistobeabletoisolateasubjectagainstthebackgroundaswithflowerphotography.

Byusingalongerfocallengthandalargeaperturethedepthoffieldissignificantlyreducedallowingthesubjecttobeisolatedagainstitsbackground.Thisisausefultechniqueifthebackgroundhasalotofclutterandwoulddistractfromthesubject.

ControllingExposure:ShutterSpeedThepurposeoftheshutteristhesameastheapertureinthelens,itisusedtoregulatetheamountoflightreachingthesensor.Itdoessobysettingthetimethatthelightfromthelensfallsuponthesensorsurface.Incompactandbridgecameras,theshutteriswithinthelensitself.UnlikeaDSLRcamerainwhichispositionedjustbeforethesensoritself.

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Thishasasignificantadvantagethatitcanbeusedtosynchroniseflashatanyoftheavailablemechanicalshutterspeeds.Theprimaryreasonphotographerswillchoosetoshootwithshutterpriorityistoenablethemtodictatetheamountofsubjectmotionblurintherecordedimage.Choosingashortshutterspeed(like1/500sec)allowsthecameratocapturefastmovingsubjectsi.e.itfreezesthesubjectmotion.Usingalongershutterspeed(like1/4sec)allowsanysubjectwhichhasmotiontobecapturedwithsubjectmotionblur.Thisisthetechniqueusedtocapturesilkyflowingwaterorclouds.

Shutterspeedallowsformoreexposurecorrectionthanapertureasithasafarbiggercontrolrangefromsecondsto1/8000secondgivingasmuchas18stopsofcontrol!Whenselectingashutterspeedtofreezesubjectmotionitisimportanttoconsiderboththedistanceandtheangleatwhichthesubjectismovingrelativetothecamera.Asubjectmovingacrosstheframeatashortdistancefromthecameraneedsanexposurewhichisfasterthanthesamesubjectmovingatthesamespeedfurtherawayfromthecamera.

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ControllingExposure:ISOAlthoughthismethodcontrolsexposureitisunliketheapertureorshutterspeedcontrolswhichdirectlyadjusttheamountoflightreachingthesensor.AsIpreviouslymentionedtheISOcontroldirectlyadjuststheamplifiergainoftheanalogueoutputfromthesensorpixels.However,thereisadireconsequenceofusingthiscontroltosettheexposure.Aswithallformsofamplificationnotonlyistheactivesignalamplifiedbutalsoanynoisethatisinthesystemisamplifiedaswell.ThatisthereasonthatIkeepstatingthatitisalwaysbesttousetheBaseorNativeISOthatthecamerahas,inordertominimisethenoiseintroducedintothesystem.Inmostdaylightlightingthisisusuallynotaproblem,infactinsomecountriesbrightsunshineisapositivedisadvantagenecessitatingtheuseofNDfiltersifyouwanttoshootwithlargerapertures.

NoiseintheDigitalCamera:Inourdigitalcameraprocessingsystem,wecanidentifythreedistinctsourcesofnoise.Thisnoiseaffectsimagesharpnessandcontrastandwemusttakeappropriatestepstoensurethatthenoiseintroducedisaslittleaspossible.Firstly,lightisanelectromagneticwaveandassuchhasnoise,notunlikethenoisethatyouhearonaradiotransmission.Thisnoiseisusuallyinproportiontotheamplitudeofthesignalitself.Ifyouhavelotsofsignalamplitude,thennoiseisn’tusuallyaproblem.Thisiscalled“shotnoise”.Ifyouareshootingwithgoodambientlight,thenthesignaltonoiseratioisveryhighandnoiseismainlyinsignificant.However,shootinlowerlightlevelsandincreasetheISOthenthesignaltonoiseratiodecreasesandnoisebecomesasignificantpartoftheimage.Shotnoiseisthemostsignificantofthethreenoisesources.

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Thesecondnoisesourceiscalled“readout”noiseanditrelatestothevariationsinthevoltagereadoutfromthesensorpixels.Thisdoesn’tvarywithchangestoISOhoweveranynoisewhichisintroducedatthisstagewillbeamplifiedbythechangesinISO.Ironicallyascamerasarenowbeingmadetoshootatfasterframeratesandrequiredtooutput4Kvideoat60fpsthe“readout”noiseisincreasing!Thethirdsourceofsystemnoiseis“darkcurrent”.Darkcurrentnoiseiscreatedbyelectronsthatemergethroughthermalprocessesinthepixel.Thenumberofelectronsincreaseswithincreasedexposuretimeandtemperature.Darknoisecanbereducedbycoolingthesensor,whichremovesinherentenergyfromthesensor,thusreducingthenumberofrogueelectrons.Inconsumercameras,thisprocessofcoolingthesensoritnotnormallyemployed.Itispossibleforthesensortoheatupquitesignificantlywhenusingthevideomodesanditiscommontoseeincreasesinnoisecapturedinstillimagesiftheyareshotimmediatelyaftershootingvideowiththecamera. So,insummary,noiseisinevitableintheprocessofconvertinglightenergyintoadigitalimage.However,therearetwootherfactorswhichalsorelatetothis.Sizeoftheactualpixelandthesensortechnology.Largephotosites(pixels)arelesspronetotheissuesofshotnoisesoevenifyouhavealargeformatcameraifthepixeldensityrequiresthatthepixelsizeisreducedthenalthoughresolutionmaybeimproved,noiseperformancemaybedegraded.SecondlyreadoutnoiseismoreofanissuewiththelatestgenerationCMOSsensorsaseachpixelnowhasitsownamplifier.

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CCDdevicessufferedlessreadoutnoisebutmanufacturingcostsweresignificantlymoreandtheabilitytoreadoutthedataatfastenoughspeedsforeven1080pvideosadlyprecludethemfrommoderncameras.So,insummarychangingapertureorshutterspeedaretheonlywaystoaffectanexposurechangeunlesstheoptimumexposureiseitherimpossibleorundesirablewherechangingISOistheonlyalternative.

WhiteBalance:Whilstwhitebalancedoesnottechnicallyplayanypartinexposuredetermination,especiallyshootingintheRAWfileformatitdoeshaveaverysignificantimpactonthewayJPEGimagesareproduced.Thereasonforthisisthatthetemperatureoflightcanvaryduetothetimeofdayorthelightsource.Itcanrangefrom“warm”to“cold”–asunriseorsunsetbeing“warm”andimagesshotinstrongshadowcanappear“cold”.Ourperceptionofcolourremainsconsistentnomatterwhatthelightsourceis.Awhiteobjectwilllookwhitewhenilluminatedbytheraysofsunsetorindeepshade.Thecamera,ontheotherhand,willshowpredominanceofred/yellowinthesunsetandblue/cyanintheshadowimage.Withyourcamera,thereareafewoptionsavailabletoyoutotryandensurethecamerarecordswhiteaswhiteirrespectiveoftheilluminationcolourtemperature.Thefirstoneistotrustthecamera’sAutoWhiteBalance.TheaccuracyofmodernwhitebalancesystemshasvastlyimprovedinrecentyearsandnowAWBisaviablesolutionforJPEGonlyshooters.

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Secondlyyoucouldrelyonthenearestcamerapre-setoptionstorecordthescenewithperfectcolours.Thiscouldbedaylight,cloudy,flashetc.,

ThirdlyyoucandialinthecorrectDegreesKelvinofthelightsourceinthe“K”settingmode.

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MyfinalalternativeforyouistouseaneutralgreyreferencecardandshootthefirstimageincludingthisreferenceintheimageandshootintheRAWfilemode.UsethistosetthecorrectwhitebalanceinRAWprocessing,byusingtheWBpickertool,andifthelightdoesnotchangeduringtherestoftheexposuresyoucanusePhotoshop’sorLightroom’sbatchprocessingmethodtosetthewhitebalanceofalltheassociatedfiles.Settingwhitebalancecanoftenbeessential–forexampleinproductadvertisingphotographyhoweverforgeneralphotographyitmightnotalwaysbedesirable.Asanexample,ifyouareshootingalandscapeatdawnorduskthelightwillappeartobemuchwarmerthanatanyothertimeoftheday.Ifyouweretouseamethodwhichrecordedtheactualwhitebalanceofthescenetheimagewillappearmuchcoolerthanwhatyouexperience.Thebestsolutionhereistosettheaccuratewhitebalancepointbutinpostprocessingapplyawarmingfilteror,ifyoushootJPEGonly,youcouldusethesunsetfilterinthecreativefiltermode.

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ExposureandMetering:We’veseenhowaperture,shutterspeedandISOdirectlyaffectexposurebuthowdoweknowwhatcombinationofthesesettingswillgivethecorrectexposureforanygivenscene.Asanexample,takealandscapeilluminatedbyafullmoononaclearnight.Meteredwithahand-heldexposuremeteritmighthaveanexposurevalueof-2withanexposureof8secondsatF4withanISOof100.ShootthesamescenebyovercastdaylightandthemetermayshowanEVof13.IfyouusedthesameapertureandISOtheshutterspeedwouldbearound1/100secondtoobtainthecorrectexposure.Whatthisshowsisthefactthatweneedtomeasurescenebrightnesstodetermineexposure.Convenientlyalldigitalcamerashaveaveryaccurate(1/3EV)exposuremeterbuiltinthatcanmeasurethescenebrightness.Additionally,thesemetersalsoprovideadirectillustrationofthecombinationofaperture,shutterspeedandISOneededtocreatethecorrectexposure.

Asyoumayhavediscoveredthemetergetsyouperfectexposuresinmostscenesituation.Thereareanumberthoughofinstanceswhereyoumayfeelthattheexposurewasquiteasgoodasitoughttohavebeen.Let’slookatwhythismightbethecase.Allinbuiltcamerameteringsystemssufferfromtwoproblems.

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Thefirstisthattheymeasurethesceneusingreflectedlightfromthesceneratherthantheambientlightfallinguponit.ThisisoftenreferredtoasTTLorthroughthelensmetering.Thesecondproblemisthattheyarecalibratedbasedupontheassumptionthatallphotographedscenesintegrateouttoaneutralgrey.IthinkhistoricallyKodakanalysedthousandsofcustomernegativesandarrivedattheconclusionthatthe“average”scenereflectancegavea18%reflectanceandthatbecamethestandardforthephotographicindustryandmanytesttargetscalled“Shirleys”wereproducedforprofessionalphotofinisherstocorrectlysetuptheirfilmprocessing,printercalibrationandpaperprocessing.IhavefondmemoriesofseeingtheseShirleysbeingdisplayedoncolournegativeanalysersandworkstations.

AtypicalKodak“Shirley”withthedensitometermeasurementpatch

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MeteringModes:Allourdigitalcamerasofferarangeofmeteringoptionswhichtheusercanselectdependinguponthescenetypecomplexitytogetthecorrectexposure.Theseare:Fullscreenevaluative/matrixmode.Thismodedoesn’trelyonjustscenebrightness;theytakearangeofmeasurementsfromdifferentareasoftheimageandthencomparethesereadingstoasetofparametersstoredwithinthecamerafirmwaretorecognisehowthesceneshouldbemetered.Forexample,ifthecameraisusedtophotographabacklitportraitandthemeteringbasedtheexposureontheaveragesceneitwouldprobablyresultinanunderexposedimage.Ifthecamerawassettoevaluative/matrixmode,thenthesystemwouldrecognisethisfactandadjusttheexposureusingpositiveEVcompensationtobrightentheimage.Thesesystemsaregettingmoresophisticatedandcanalsobaseexposureonnotonlybrightnessbutcolourinformationaswell.Centreweightedmode.Thismoderatherthanmeteringthesceneittakesareadingfromthecentreportionoftheimage.Inourbacklitportraitexamplethiswouldproduceamuchbetterresult.Thisisbecauseanybackgroundbrightnessislargelyignoredintheexposuredetermination.Spotmeteringmode.ThismodeandthePanasonicprecisemodeisonewhichisbecomingmorecommoninuse.Thereadingisrestrictedtojustafewdegreesofviewallowingyoutoselectspecificareastomeasuretheexposure.Youcaneventargetthehighlightareasthentheshadowareastodeterminethetotalcontrastwithintheimage.Thismodeisextremelyusefulwhenyouarephotographingasubjectwhichiseitherbrighterordarkerthanitsbackground.

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Byusingthisprecisemeasurementspotitiseasiertogetthecorrectexposureforthatarea.

TrickyExposureSituations:Quiteoftennomatterwhatmeteringmodeyouusethecamerawillstillgettheexposureincorrect.Thisisbecausethefundamentalcalibrationisdesignedtomakeeveryreadingresultinthe18%reflectedvaluebeingachieved.Thismayresultindarksubjectsbeingrecordedtoolightandlightscenesbeingrecordedtoodark.Onesolutioninsituationsliketheseistouseatargetspecificallydesignedforthispurpose–an18%greycard.Asitsnamesuggestsitisnothingmorethanaspectrallyneutralgreycarddesignedtoreflectan“average”amountoflightfromtheincident/ambientlightthatisfallingonthesubject.So,ifyouplacethiscardinthelightthatyouarephotographingthescenewithandusethecameraspotmetertomeasuretheexposurefromthiscard.RecordthevaluesuggestedbythemeterontheLCDandthensetthesevaluesintothemanualexposuremodeofthecamera.Returningtoourbacklitportrait,ifyouweretoaskyoursubjecttoholdthistargetcardinfrontofthemandyoupointthespotmeteratthiscardyouwillgetanexposurereadingthatyoucanthensetinthemanualmodeandgetaperfectexposure.ThishighlightsthefundamentalflawinrelyingupontheTTLmeteringmodeofthecameraundersubjectconditions.Togetthemostaccurateexposurereadingitisbettertousethisreflectedlightfromthegreycardmethodoruseaspecialhandheldmeterinitsincidentlightmetermodetogathertheexposurereading.IfyouareusingApertureorShutterprioritymodestocaptureimagesyoumay,overaperiod,developa“feel”forthosespecificsceneswhichconsistentlyfoolthecameraexposuresystem.

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Suchisthecasewithsnoworbeachscenesinbrightsunlightwhichinherentlyhaveabrightbackground.Inatypicalsnowscene,itmaybenecessarytousesomethingoftheorderof2-3F-stopsofexposurecompensationtogetanexposurewhichdoesn’tlookgreyorunderexposed.

Ifyouweretousethecamerahistogramfeatureitwouldneedtohavethehighlightssetagainsttheright-handsideofthegraphhowever,itshouldnotresultinthehighlightdetailbeinglostduetoblowouts.

DynamicRange:Oneoftheskillsthatyouwilldevelopasyouprogresswithyourphotographyistheenvisioninghowtheactualscenesbeforeyouarerenderedasadigitalimagebythecamera.Wehaveseenthatinshootingabacklitportraitthiscanquicklyresultinasilhouettebeingproducedandabrightsnowscenebeingunderexposed.Inotherwords,whatoureye“sees”isnothowthecamerarecordsthesceneforus.

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Wehaveseentechniquestocompensateforthesemeteringfailurestoobtainanexposurethatmoreaccuratelymatchesourexpectationsofourimage.Theproblemisthatthecamerahasamuch-reducedrangeoftonesthatitcancapturewithintheoneexposurecomparedtoourownvisionsystem.Theverybestofconsumercamerasmaybeabletocaptureabout12F-stopsofdifferencebetweenhighlightandshadow.Ithasbeenestimatedthatoureyescanseewitharangeofabout24F-stops!Smallersensorcamerassuchascompactpointandshoottypesorbridgecamerasmayonlybeabletorecordatotalrangeof8to9F-stops.Thisrangeiscalledthe“dynamicrange”andisoneofthemostproblematicareasinimagecapture.DynamicrangeisrelatedtopixelsizeandISOamplification.Largersensorswithlargerpixelshaveawiderrangethansmallersensorswithsmallerpixels.AsISOisincreasedtogetourexposurescorrectsonoiseisintroducedintothesystem.Noisereducescontrastwhichdirectlyreducesdynamicrange.Itisafactbutifourscenethatwewanttocapturefaithfullyhasatonalrangewhichexceedsthatbywhichthecameracancapturewewillendupwithacompromiseastowherewewillsacrificesomeimagedetail.Thiswillbeeitherthehighlightareasortheshadowareas.Whichoneyouchoosewilldependuponthescenecontent.Ifyouimagineshootingaweddingsceneitisdesirabletocapturehighlightdetailsinthebridesweddingdressthantextureinthegroom’sdarksuit.Again,thehistogramwillbeyourfriendheretosetthehighlightareasagainsttheright-handsideofthegraphandyouwouldideallyshootintheRAWmodesothatyoucanextractasmuchhighlightdetailaspossible.

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JPEGimagesmaycompresssomuchofthehighlightdetail.

So,whatcanbedonetoimproveourchancesofcapturingthescenecorrectly?WellthebestadviceIcangiveyouhereistostopshootingscenesthatyouknowarewellbeyondthedynamicrangeofthecamera.Waituntilthelightfallinguponyoursubjecthasamuch-reducedcontrastrange.Shootingflowersinbrightsunshine,forexample,causestoomanyhighlightsthatifyouweretosettheexposuretocapturedetailintheseareastheshadowsandmid-toneswouldbeverymuchunderexposed.Itwouldbebettertowaitforovercastlightingorcreateyourowndiffusedlightingbyplacingawhitenylondiffuserbetweenthesunandtheflower.Wellthisadvicedoesn’tappeartobeofferingmuchpracticaladviceinshootinginthesesituationsbuthonestlythebestadvicewouldbetolearnhowthecamera“sees”theimageratherthanbelieveyoureyes.

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AtechniquethatIlearnedwasto“squint”myeyes.Thishastheeffectofreducingthenaturaldynamicrangeofoureyesthusbringingthemnearertohowthecamerawillrecordtheimage.

SomeThoughtsonControllingDynamicRange:Wehaveseenpreviouslyhowtocontrolexposurebyadjustingaperture,shutterspeed,ISOoranycombinationofthem.Insomesituations,particularlylowlightones,wecanoftenbeforcedtoraisethecameraISObecausewewanttohaveaspecificdepthoffield,orweareatmaximumaperture,andhaveashutterspeedwhichisalreadyonthelimitofcapturingsomeamountofblurthroughsubjectmotion.Inthissituation,ouronlyoptionistoincreasethecameraISO.AsIhavepreviouslymentionedincreasingISOnotonlyincreasesimagenoiseitalsoreducesthedynamicrangethatthecameracanrecord.Inthissituation,theonlyviableoptionistoaddsomeadditionallightintothescene.Thismightbebyusingsomeadditionallights,theuseofareflectortobouncelightbackintothesubjectortousesomeformofflash.

Inthispictureofmydaughter’sweddingIhadtousefillflashtocompensateforthefactthattheywereinabacklitsituationandIwantedtoretaintheambientbackgroundwhichwouldhavebeenblownoutifIhadusedexposurecompensation.

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Inthestudio,wecancontrolourlightingprecisely.Wecanmeterthehighlightsandtheshadowsandensurethattheyfallwithinthecamerasdynamicrange.Iftheyexceedit,wecanaddfilllighttoreducethecontrast.Ifweareshootinglandscapesquiteoftentheskiesaremuchbrighterthantheforegroundandagainresultinasituationwherewecannotgetasuitableexposuretoshowdetailinbothareas.Insomecircumstances,itispossibletoreducethecontrastbyusinggraduatedneutraldensityfilterswheretheupperportionofthefilter“holds”backsomeofthelightreachingthesensor.Whilstthisworkswellhowever,ifthelandscapehasobjectssuchastreesormountainpeakswhichriseintothisareathesetoowillbedarkenedandlookartificial.Thereisalsoatechniquewhereyoucancapturemultipleimagesatdifferentexposures(exposurebracketing)andthenmergetheminyoureditingprogramusinglayermaskingtechniques.Thisisnotwithoutproblems.Ifthereisanysubjectmotionthiswillbeevidentinthemergedimages.OnwayaroundthisistoshootintheRAWmodeandthenmakeseparateJPEGimagesfromtheoneimage.Oneforhighlights,oneformid-tonesandfinallyonefortheshadows.Again,thethreeimagescanbecombinedtogivethebestcompromise.Somecamerashavethefacilitytoproduceanin-cameraimagewithincreaseddynamicrange.Again,thecameracantakeseveralimagesandthencombinetheseintooneimageinaprocessusuallyknownasHDRorHighDynamicRange.TheseimagescanbequiteunpredictableintheiroutcomeandIfindtemhardtoenvisionbeforeItaketheshot.IamnotafanofthehighlyprocessedHDRimageswhichhaveextremedistortionsofthesubject’soriginalcontrast.

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Conclusions:WellIhopeinthisshortguidetoexposureithasgivenyousomeanswerstoproblemsthatyoumightbeseekingananswerto.Ifyouneedmoreinformationonshootingwithflashtoreducedynamicrange,thenIdohavetheUser’sGuidetoFlashagainavailableasafreedownloadonmyPhotoblogDownloadspage.https://www.grahamhoughton.com/download-section/Ifyouwanttoprovideanyfeedbackonthisguide,pleasedosobyemailingmeatsupport@grahamhoughton.com

GlossaryofPhotographicTerms:Aperture-thevariableopeninginthelensthroughwhichlightpassestothefilmordigitalsensor.Measuredinf-stops.Iliketocompareittoyourpupilwhichopensandclosestoallowlighttoenteryoureyedependingonthebrightnessleveloftheroom.

Bracketing-takingaseriesofimagesatdifferentexposuresorEV.YoumayseeasettingonyourcamerathatsaysAEB(autoexposurebracketing).ThisisoftenusedwhencreatingHDRimagesorindifficultlightingsituationswhereyoumaywanttohavearangeofexposuresfromlighttodark.

Bulb-the“B”settingonyourcamerawheretheshutterremainsopenedforaslongasthebuttonorcablerelease(remotetrigger)ispressed.

EV-ExposureValueisanumberthatrepresentsthevariouscombinationsofapertureandshutterspeedthatcancreatethesameexposureeffect.

Exposurecompensation-modifyingtheshutterspeedoraperturefromthecamera’srecommendedexposuretocreateacertaineffect(overorunderexposing)–usuallyusedintheShutterPriorityorAperturePrioritymodes.Representedbyalittle+/-buttononyourcamera.Yourcamerareadslight

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bouncingoffyoursubjectandisdesignedtoexposeformediumgrey.So,whenphotographingasubjectthatislighterordarkerthan18%grey,youcanusethissettingtotellthecameratheproperexposure.

Exposure-thetotalamountoflightreachingthecamerasensor.Itiscontrolledbythesettingoftheaperture,shutterspeedandISO.SeemyExposureTriangleformoredetails.

F-stop-isameasureoftheapertureopeninginthelensdefinedbydividingthefocallengthofthelensbytheaperturediameter.Sequenceoff-stopsthataremultiplesofthesquarerootof2(1.4):givingarangeof1,1.4,2,2.8,4,5.6,8,11,16,22,etc.Rememberthateachstepisdoubletheamountoflight.

ISO-standsforInternationalStandardsOrganizationandrepresentsthesensitivityofyourcamera’sdigitalsensortolightandsubsequentsignalamplification.Thelowerthenumber(ISO100),thelesssensitive,thehigherthenumber(ISO3200)themoresensitive.AhigherISOallowsyoutoshootinlowlightconditions

Shutterspeed-theamountoftimetheshutterisopenedduringanexposure.Theshutterspeedcontrolssubjectmotionblur.Useafastspeed(like1/2000thofasecond)tofreezemotion,oraslowone(1/4ofasecondorlonger)toblurmovingobjects.

Zoomlens-anylensthathasvariablefocallengthssuchasa24-70mmor18-55mm.Youzoominoroutbyrotatingthebarrelofthelens.

Remotetriggerordigitalcablerelease–adevicethatallowsthecameratobefiredwithoutpressingthebuttonortouchingthecamera.Helpseliminatemovementofthecameraduringlongexposures.

Macrolens-onethatfocusesveryclosetothesubjectallowingfor1:1reproductionsizeoftheobjectorlarger.

Cameraresolution-expressedinmegapixelsisthedimensionsyourcamera’ssensoriscapableofcapturing.Thisisnottheonlyfactorinimagequality,butgenerallythelargethenumber,thelargerprintsyoucanproducefromitwithoutlossofquality.

FileformatJPEGversusRAW-TheFZ300/330hastheabilitytoshootbothformats.IfyouchooseJPG,thecamerawillshootaRAWfile,processitusing

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thePhotostyleyou’veselectedinyourmenu,saveitasaJPGanddiscardtheRAWversion.IfshotinRAWtheresultingfilewillbelarger,carrymoreinformation(butthesamepixelresolution,seeabove)andrequiresoftwaretoprocess.Itgivesyouthephotographermorecontroloverthefinallookofyourimage.

LightingandPortraitPhotographyTerms

Ambientlight-alsoreferredtoasavailablelight,isthelightthatisoccurringinthescenewithoutaddinganyflashorlightmodifiers.Thiscouldbedaylight,orartificiallightsuchastungstenorLEDLights.

Mainlightorkeylight-isthemainlightsourceforaphotograph.Itcouldbethesun,astudiostrobe,aflash,areflectororsomethingelse.Butitisthesourceoflightthatisproducingthepatternoflightonthesubjectwiththemostintensity.

Filllight-isthelightsourcethatissecondarytothemaillight.Itisusedto“fill”intheshadowstoadesireddegree.Itcanbeproducedbyusingaflash,areflector,orastudiostrobe.

Lightingpattern-thisisthewaythelightfallsonthesubject’sface.Apatternoflightandshadowthatiscreated.

Lightingratio-isacomparisonbetweentheintensity(brightness)ofthemainlightandthefilllightandthusthedifferenceofthelitandshadowsidesofthesubject’sface.

Incidentlightmeter-isahandhelddeviceseparatefromyourcamerathatmeasurestheamountoflightfallingonasubject(asopposedtothereflectivereadingyourcameratakeswhichislightbouncingoffthesubjectbacktothecamera).Itisnotfooledbythebrightnessrangeofthesubject,whereasincamerareflectivemeterscanbefooled.

Reflector-adevicethatisusedtoreflectlight,generallybacktowardsthesubject.Itcanbeaspecializedfactorymadereflectororassimpleasapieceofwhitecardboard.

Lightmeter-adevicethatmeasurestheamountoflightinascene.YourFZ300/330hasonebuiltin,itusesreflectivereadings(lightbouncingoffthesubjectcomingbackthroughthelens[TTL])

Remoteflashtrigger-adeviceusedtofireremoteflashunitsoffcamera.

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Subtractivelighting-asthenameimpliesitisthetakingawayoflighttocreateadesiredeffect.Commonlyitinvolvesholdingareflectororopaquepaneloverthesubject’sheadtoblocklightfromaboveandopendeepeyeshadowscausebyoverheadlighting.Itcanalsomeanholdingablackreflectoroppositeyourmainlighttocreateadeepershadow,reflectingblackontothesubjectinsteadoflight.

Hardlight-harshlightsuchasproducedbybrightsunlight,asmallflashgun,oranon-cameraflash.Itproducesharshshadowswithwell-definededges,contrast,andtexture(ifusedatanangletothesubject).Emphasizestexture,linesandwrinkles,andusedtocreateamoredramatictypeofportrait.

Softlight-diffusedlightsuchasfromanovercastsky,northfacingwindowwithnodirectlight,oralargestudiosoftbox.Thistypeoflightproducessoftshadowswithsoftedges,lowercontrast,andlesstexture.Generallypreferredbymostweddingandportraitphotographersasitflatterthesubjectmore.

Flashsync-simplyputisthesynchronizationofthefiringofanelectronicflashandtheshutterspeed.Youneedtoknowwhatshutterspeedyourcamerasyncsat,otherwiseifyoushoottoofastashutterspeedyoumaygetapartiallyilluminatedimage.FortheFZ300/330becauseofthein-lensshutterflashcanbesynchedatanyoftheavailableshutterspeeds.

SomeSlangPhotographicJargon

Becomefamiliarwiththemsoyoucanwalkamongtheproswithconfidence!

Fastglass-referstoalenswithaverylargemaximumaperturesuchasf1.8orf1.2.“Fast”asin,itallowsyoutoshootatafastshutterspeedduetothelargeaperture.

Chimping-slangtermmeaninglookingatthebackofthecameraaftereveryimage.Spendingtoomuchtimereviewingimagesoncamera,notenoughtimeshooting.

Bokeh-oftenmispronounced“bow-kay”or“bow-kuh”itiscorrectlypronouncedas“bo-ke”likethekeinkettle.Itisusedtodescribedtheoutoffocusblurredbitsinthebackgroundwhen“fastglass”isused.Mostoftenbokehoccurswheresmalllightsourcesareinthebackground,farinthedistance.

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DepthofField-(DOForDoF)-thedistancebetweenthenearestandfarthestobjectsinyourscenethatappearinfocus.Itiscontrolledbymanyfactorsincludingtheaperture,lensfocallength,distancetosubject.

Circlesofconfusion-closelyrelatedtotheabovebokeh,thetextbookdefinitionis:thelargestblurspotthatisindistinguishablefromthepointsourcethatisbeingrendered.Objectsoutsidethedepthoffieldofanimagethatthehumaneyecandetermineas“outoffocus”.

Hyperfocaldistance-oftenusedbylandscapephotographers,itisthefocusdistanceprovidingthemaximumamountofdepthoffield.

Gobo-somethingusedtoblockunwantedorstraylightfromfallingontothesubject.Oftenareflector(usingtheblackside)canserveadualpurposeandactasagoboaswell.

Scrim-atranslucentdeviceusedtodiffuseandsoftenthelight,couldbeareflectorwithatranslucentpaneloroption.Also,usedonmoviesetsscrimscanbemadeextremelylarge,severalfeetacross,andclampedinplacetocreateshadewheretheseisdirectsunwithoutit.

Shutterlag-theslightdelayfromthetimeyoupresstheshutterbuttontothetimeitfiresandopens.

Chromaticaberration-intermsoflensopticsitisthefailureofthelenstofocusallcolours(RGB)atthesamepoint.Itshowsupascolourfringesinareasoftheimagewheredarkmeetlight(thinkedgeofabuildingagainstthesky).Itismorecommoninwideanglelenses,andthoseofinferioroptics.Itiscorrectable,tosomedegree,usingPhotoshop,Lightroom-orsoftwareofyourchoice.

Rearshuttercurtainsync-bydefaultmostcamerasaresettofrontcurtainsyncwhichmeansthatiftheflashfires,itdoessoatthebeginningoftheexposuretime.Bysettingtorearshuttercurtainsyncitfirestheflashattheendoftheexposuretime.Thedifferenceinsomecasesmebenegligible,butinshootingamovingsubjectfrontsyncwillputanymotionblurinfrontofthesubject,whereasrearsyncwillplacetheblurbehindthesubject.Neitheriswrong,justpreference.

Camerashake-thisisablurryimagewhichhasresultedfromaninsufficientlyfastenoughshutterspeed,whilehandholdingthecamera.Sohowslowistooslow?Manywillsaythat1/60thofasecondistheruleofthumb.Itend

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torecommend1overthefocallensofyourlensinstead,asthelongerthelensthemoreamplifiedanyshakewillbecome.

Lensflare-occurswhenthelightsourcehitsthelensdirectly,itcanmanifestasahazylookingimageorartefactssuchascirclesoflight.Somephotographersdesirelensflareandpositiontheircameratocreateitanduseitasacompositionalelement.

Kelvin-istheabsolutemeasurementofcolourtemperature.OnyourcameraundertheWhiteBalancesettingsyoumakeseea“K”setting.ThisallowsyoutoadjustthecolourmanuallybydegreesKelvin.Thelowernumbersrepresentwarmercolourslikeorange(tungstenlight)andthehighernumbersarecooler(blues).

NDfilter-standsforneutraldensityfilterwhichisafilterdesignedtogoinfrontofthelenstoblockoutsomeofthelightenteringthecamera.Oftenusedbylandscapephotographerstobeabletogetslowshutterspeedswhenphotographingwaterfallsandstreamsinfulldaylight.

Panning-theactofusingaslowshutterspeed,andmovingthecamerainthesamedirectionasamovingsubject,duringtheexposuretocreateablurredbackground.

Stoppingdown-theactofclosingtheaperturetoasmalleropeningsayf2.8tof4.

TTLandETTL-standsforThroughtheLens,referstothemeteringsysteminregardstoflashexposure.Theflashemitslightuntilitisturnedoffbythecamerasensor.ETTLisevaluativethroughthelensmeteringandfiresa“pre-flash”toevaluateandcalculateforlostlightthencompensatesandfiresthemainflash.Ithappenssofastyoudonotseetwoflashes.

Goldenhour-alsocalled“magichour”isthehourrightbeforesunsetorrightaftersunrise.Thesunislowonthehorizonanditisanoptimaltimeforphotography.

Blownout-havinghighlightsthatareoffthechartontherightsideofthehistogram,havingnodetailinthewhiteareas.

Clipped-similartoblownoutbeingoffthehistogram,butitcanalsoapplytoshadoworblackareasoftheimage.

Selfie-aselfportrait

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SOOC-straightoutofcamera,nopostprocessingoreditingdone.

Wideopen-usingyourlenswiththeapertureatthewidestsetting(f2.8forexample)