1 Eachof thefivemeteringsegments
measuresthelightin itsareaand
convertstheinformationtodigitalvalues.
2 Informationonthelensin use– type,
numberof apertures,focallength– is
gatheredandfedintothecamera’scomputer.
3 Moredata– degreeof contrast,brightness
compositionpatterns,percentageof extra-
brightareas,percentageof extra-darkareas,
generallightintensity– arealsofedintothe
camera’scomputer.
4 Aninitialexposureis analysedandselected.
5 Theparametersfromphase4 arecompared
tostoredsimulatedscenepatternsfrom
tensof thousandsof picturetypesin the
computer’smemory,andtheexposureis
readjustedaccordingly.
6 Scenedatafromphase3 is comparedwith
scenedatafromphase5 and a final decision
onexposureis computed.
7 Theshutterfires.
Allthishappensasthelensis stoppeddown
toitsshootingaperture,soif theaperture
doesn’tshutdowntopreciselyitscorrect
setting,orif thelightchangesin thelast
split-second,theexposureis stillmeasured
andsetcorrectly.A dualprogrammode
ensuresthatif a lensof 135mmorlongerfocal
lengthis in place,theautomationswitchesto
highershutterspeedsautomatically.In shutter
priority,if thechosenspeedmeansoveror
underexposurebecausethelenshasrun
outof aperturesforcorrectexposure,the
automationoverridesthesetting and sets
a faster or slower speed.TestbenchThelenses
Trueto Nikon’sphilosophy,theFAusesthesame
lensmountasthe 1959 NikonF. Althoughthe
mounthasremainedmuchthesame,certain
modificationshavebeenmadeovertheyears.
Fromthestart,Nikkorlensesuseda smallfork-like
appendageontheapertureringthatlinkedwith
a pinin thecamerabodytokeepthecamera’s
meterinformedabouttheaperturesetting.In 1977NikonintroducedAutomatic
MaximumApertureIndexing(AI)Nikkorlenses
withsmallridgesin theirmountsthatmatched
toa feeleronthebodymount,sothatthe
maximumapertureof thelensin usewas
automaticallyindexedtothemeterin the
body.In 1981,in preparationforthelaunch
of theFA,NikkorAIlensesweremodified
andcalledAI-SNikkors.Themodificationgave
linkstothelens’saperturecontrol,making
shutterpriorityandprogrammodespractical
forthefirsttime.
Tomakethemostof themeteringmodeson
theFAit shouldbeusedwithanAI-SNikkor
lens,oroneof theNikonE-serieslenses
launchedin 1978fortheEMcamerawhich
havesimilarcapabilities.Becauseof the
universalityof theNikonF mount,AI-Slenses
canbemountedonoldercameras,butit is
inadvisabletomounta non-AI-Slenson
theFAastheslightdifferencesin themount
of olderlensescandamagetheintegral
connectionsin thebody.
Becausethesubtledifferencestothelens
mountonAI-Slensesaren’talwayseasyto
spot,theeasiestwaytoidentifyanAI-Slens
is tolookat theaperturescalering.Onan
AI-Slens,theminimumapertureis always
etchedin orange.
TheNikonFAstandsat thecentreof a
hugesystemof lensesfrom6mmfisheyeto
2,000mmtelephoto,plusmotordrivesfor
3.2framespersecond,close-upequipment,
speedlightswiththrough-the-lens(TTL)flash
meteringthatreadthelightoffthefilmbeing
exposed,interchangeablefocusingscreens,
databackanda hostof smalleraccessories
toonumeroustomention.
Forthefilmenthusiast,it’sstilla great
cameratouse.Forthecollector,it’san
amazingexampleof 1980stechnology,
andforthosewith feet in both camps,
it’s irresistible.Theorangecolouronthesmallestaperturesettingis an
easywaytoidentifylenscompatibilitywiththeFA,hereon
50mm Nikkor AI-S (left) and 50mm Nikon E-series lensesBelow: When it was launched, the FA stood at the centre of Nikon’s huge system of lenses and accessoriesFROM NIKON FA BROCHURE PUBLISHED IN 1983 © NIKON CORPORATION
Awhitehorseagainsta
predominantlyblack
backgroundis thekindof
subjectthatAMPmetering
takes in its stride