Digital SLR Photography - UK (2019-12)

EQUIPYOURSELFWITHTHESKILLSTOCAPTUREBEAUTIFULPORTRAITIMAGES

USINGA VARIETYOFAPERTURESBYFOLLOWINGA FEWBASICPRINCIPLES

APERTURES FOR PORTRAITS

P

ORTRAITS,OFALLthephotographic

subjectmatters,arethemostflexible

andopentocreativitywhenit comes

toapertureuse.Theysuitalmostevery

aperture,fromf/1.2tof/16andeverything

in-between.It’smostcommon,however,

forheadshotportraitstobecreatedin the

regionoff/1.8tof/5.6,dependingonthe

focallength.Whenyou’rephotographing

environmentalportraitsthatencompassa

widersceneorgroupportraits,ofmorethan

threepeople,you’lllikelyneedtostopyour

aperturedowntof/8orevenf/11asthe

depthoftheareayouneedtobeacceptably

sharpincreases.Similarly,if flashis usedyou

maybeforcedtoworkwithmid-apertures

toavoidoverexposingtheimage,if youfind

yourselfwithNDfiltersorhigh-speedflash.

Whenworkingwithnaturallight,youneed

tofindthebalancebetweenmaximising

availablelightandsufficientdepth-of-field.

ThiscanbedonewiththehelpofyourISO,

precisefocusing,yourchosenfocallength

andadjustingyourshootingdistance– not

justyouraperture.A greatwaytolearnhow

distanceandapertureaffectdepth-of-field

is to use a ‘fast’ lens, like a 50mm f/1.8 or

similar,andtopractice.Set thelenstof/5.6,

focusontheeyes,andthengraduallystop

uptheaperturetof/1.8toreviewtheresults.

Youcanalsotrydifferentcropsat thesame

aperturebymovingclosertothesubjectto

filltheframe,orfurtherawaytoinclude

contextin theirsurroundings,togiveyouan

ideaofhowyoucancontroldepth-of-field

bymovingyourfeet.Onceyou’vemastered

a standardlens,switchtoa wide-anglesuch

asa 35mmf/1.4ora telephotolenslikea

70-200mmf/2.8tocompareandcontrast.

All theselensesarepopularportraitlenses

anddeemedhigh-quality,‘fast’lensesfor

theirconstant,largemaximumapertures,

buttheyallbehavedifferently.Forinstance,

at f/1.4ona 50mmyou’reunlikelytoget

morethantheeyesin focusduetothevery

shallowdepth-of-field;butthewider

field-of-viewofa 35mmf/1.4couldgive

acceptablesharpnessfromeyestoears.A

telephotolens,however,canrendera whole

subjectsharpat f/2.8withthebackground

andforegroundgentlyoutoffocus,dueto

howit compressesperspectiveand

increasesworkingdistance.Thesebenefits

are part of the beauty of using long lenses

forportraitsasthedistanceyouputbetween

youandthesubjectprovidesample

depth-of-fieldtogetmostofa subject

sharp,butthecompressedperspective

amplifiestheappearanceofbokehby

pullingthebackgroundandforeground

closertogether.If you’reunabletoreapthe

benefitsofa fastlensanditswideapertures

duetobudget,a zoomlenscanworkfor

portraittoo,butyou’lloftenbelimitedto

f/5.6at thelongestendofa standardzoom

(18-55mm),whichis unlikelytogiveyouthe

bokehyou’reyearningfor.

Withportraits,a subject’seyesarealmost

alwaysthepreferredfocalpointsoyour

focusinghastobeprecisewhenusingwide

apertures.Single-pointAFanddifferential

focusing(seepanel)is a preferredtechnique,

althoughback-buttonfocusingis popular

withadvancedphotographers.Whileit’seasy

tofocusonyoursubject,it’simportanttonot

forgetyourbackgroundeither.As depth-of-

fieldextendstwo-thirdsbehindyoursubject,

youneedtobecarefulyourbackground

doesn’tfallwithintheareaof ‘acceptable’

sharpnessif youwanttorenderit 'bokehful'

and disguise clutter or hide distractions.

THEBEAUTY OFUSINGLONGLENSESFORPORTRAITS IS THE

DISTANCEYOUCANPUT BETWEENYOUANDTHESUBJECTTO CREATE

STUNNING BOKEH SURROUNDING A FULL-LENGTH SUBJECT

Right:Selectinga wideaperturesettingcanproduce

stunning headshots with very shallow depth-of-field.

PhotoMasterclass

Otherwiseknownasselectivefocusing,differentialfocusingis a techniquethatletsyoupreciselyplaceandisolateyour

focalpointanywherein theframeusinga wideaperture.InsteadofusingthecentralAFpoint,thismethodletsyouplace

yourfocuspointanywherein theframe,toshootpastout-of-focusforegroundorsimplypreferencea subject’seyesover

theirnose.You’llwanttocombinethistechniquewitha verywideapertureforbestresultsanda longlens,suchasa

150mm,50-150mmor70-200mm.Placeyourfocuspointovertheareaofinterest,bestpositionedin themiddleground,

using single-pointAF and your four-way control.You could alternatively lock focus and then recompose your image.

WHAT’S DIFFERENTIAL FOCUS?

54 DigitalSLR PhotographyDecember 2019

Q

ShouldI shootat mywidestaperture?

Ifyou’reusinga wide-anglelensthen

shootingat f/1.4canresultin beautifulimages,

butanyfocallengthlongerthan35mmandyou

riskworkingwitha veryshallowareaofsharpness.

Ifyourfocusingisn’tprecise,it couldmeanyou

misstheeyesandonlygettheeyelashessharp–

there’snoroomforerrororsubjectmovement.

It’sbesttobesafeandstopdowntof/2.8orf/4.5

if you’regoingforframe-fillingportraits.

Q

Toomuchofthebackgroundis in focus,

sowhatcanI dotoavoidthis?

You’vethreechoicesora combinationofall

three:openupyouraperture;movecloserto

yoursubjectfora tightercropandtherefore

shallowerdepth-of-field;and/ormoveyour

subjectfurtherawayfromyourbackgroundsoit

fallsoutsideoftheareaofacceptablesharpness.

Q

CanI useFull-Areaautofocus?

Ifyou’reshootinga groupportraitwitha

mid-aperture,youcouldgetawaywithusing

Full-Areaautofocusbutit’sstillbesttouse

single-pointAFandplacethepointoffocuson

theareayouwantsharpest,suchasthecentre.

Ifyoudon’t,andyou’reusinga wideaperture,

yourcamerawillfocusonthenearestobjectto

thecamera– usuallythenoseoreyebrows.

Q

Cana poseaffectyouraperturechoice?

Theangleofa subjecttothecamera’s

sensorcandramaticallyaffectanimage.If the

subject’sfaceis paralleltothecamera,any

availabledepth-of-fieldwillbeusedequally

acrosstheface,ensurebotheyesaresharp;if you

positionyoursubjectin a three-quarterposeto

thecamera,whichis usuallythemostflattering,

you’lllikelyneedtostopdownyourapertureto

f/5.6toensureyougetbotheyesin focus,now

that one is angled further away from the sensor.

BRET

THARKNESS

Q&A:APERTURES & PORTRAITS