Amateur Photographer – 16 August 2019

subscribe 0330 333 1113I http://www.amateurphotographer.co.ukI 10 August 2019 49

17mmcentre

22mmcentre

28mmcentre

17mmcorner

22mmcorner

28mm corner

Resolution

OurImageEngineeringtests,shotonthe42.4MP

SonyA7RIII,reveala lensthat’sverysharpin the

centreoftheframeatallfocallengths,evenat

maximumaperture.It’snotquitesospectacularin

thecorners,butstillverygood.Theoddbehaviour

atsmallapertures,withthecornersappearing

sharperthanthecentre,is probablyanartefact

of shooting a flat test chart at close distances.

Tamron 17-28mm

F/2.8 Di III RXD

Curvilineardistortion

Atitswideanglesetting,thelensexhibitsmoderate

moustachedistortion,withbarreldistortionin the

centreoftheframere-correctingtopincushion

towardstheedges.Zoomin toaround19mmand

thisneutralises,beforeturningtopincushion

distortion through the rest of the zoom range.

Shading

At17mmthelensshowsfairlystrongvignettingof

almosttwostops,whichwillbeplainlyvisiblein

imageswithclearblueskies.Thisdecreasesto

about1 stoponclosingdowntof/5.6,butdoesn’t

reduceanyfurther.Longerfocallengthsshowthe

same pattern, but lower levels of light fall-off.

17mm f/2.8 28mm f/2.8

17mm 28mm

SMIA TV = -1.9% SMIA TV = 1.6%

Untilnow,Sonyfull-framemirrorlessusers

lookingfora compactwideanglezoom

havehadoneobviousoption:theSony

16-35mmf/4.Butwiththe17-28mmf/2.8,

Tamronhasdeliveredanexceptionally

strongalternative.Likeits28-75mmsibling,

thisis a verylikeablelensthatcombines

impressivesharpnesswitha fastmaximum

aperturein a compact,lightweight,

weather-resistantdesign.Landscape

photographersin particularshould

appreciateitscombinationof strengths.

Indeedgiventheexcellenceof itsoptics,

theonlyrealquestionmarkconcernsits

limitedzoomrange.Thisis a lensthatreally

needstobepairedwitha 24mmor28mm

zoomforeverydayshooting,whereassome

photographersmightbe

happycarryingtheSony

16-35mmf/4onits

own.Butin everyother

respect,theTamron

17-28mmf/2.8is an

excellentalternativethat

offersfantasticvaluefor

money.Let’shopethe

firmcanproduceCanon

RFandNikonZ-mount

versions soon.

Verdict

LENS TEST Testbench

Excellentimagequalityis maintainedacrossthefullzoom rangeSony Alpha 7 III, 28mm, 1/250sec at f/8, ISO 100

Price£899.99

Filterdiameter67mm

Lenselements 13

Groups 11

Diaphragmblades 9

Aperturef/2.8-f/22

Minimumfocus

0.19m

Length99mm

Diameter73mm

Weight420g

LensmountSony E

(full-frame)

Data file

GOLD

Tamron17-28mmf/2.8deliversstronglyon
allthesecounts.
Indeedsharpnessis particularlyimpressive,
withthelensdescribingexcellentlevelsof
detailintothecornersevenat f/2.8.In factthe
lensoutperformsmostof itsDSLRequivalents,
illustratingtheinherentadvantagesof
mirrorlessmountsforwideanglezoomsand
vindicatingTamron’sdecisiontorestrictthe
zoomratio.Stopdowntonormalworking
aperturesof f/8tof/16andyou’llgetimages
thataresuper-sharpfromcornertocorner.
Thisperceivedsharpnessis alsohelpedby
verylowlevelsof lateralchromaticaberration:
evenif youdisablein-cameracompensation
forsomereason,you’llseeverylittlecolour
fringingin thecornersof theframe.Adobe
softwarecorrectsthisbydefaultwhen
developingrawfiles,too.
Curvilineardistortionis muchaswe’dexpect;
at 17mmlinesthatshouldbestraightalong
thelongedgeof theframeadopta noticeably
wavyappearance.Acrossmostof therest
of thezoomrange,you’llseepincushion
distortionthatgetsincreasinglypronounced
asyouzoomin.A lotof thetimethisis nothing
toworryabout,butit hasthepotentialtobe
troublesomeforarchitecturalphotography,
orlandscapeswitha cleanhorizon.
Forrawshooters,thecomplexdistortion
patternat 17mmreallydemandstheuseof
profiledcorrectionstoremoveproperly,rather
thanthosebasedonsimplesliders.Atthe
timeof writing,there’snoprofile yetavailable
forAdobeCameraRaworLightroom,but
doubtlessonewillappearin duecourse.
Enablein-cameralenscompensationand
distortionwillbeperfectlycorrectedin the
JPEGoutput.
Flareresistanceis veryimpressive,which
is importantforsucha widelens.Evenwhen
shootingdirectlyintothelight,I sawnohintof
ghostingorveilingflare.Stopdowntof/11or
smaller,andyou’llget18-pointsun-stars
thanks to the 9-bladed diaphragm.