3.Whenthedistancescaleoftheprimelensissettominimumoraroundthere,
youcanfocusonyoursubjectevenifitisbeyondtheoriginalclosestshoot-
ing
distance.
Note,however,thatpicturequalitymaysomewhatbeimpaired.
4.
Iftheprimelensisthe135mmf/2,makesureyousetthedistancescale
betweeninfinity(»)and2m(6.6ft)inordertoobtainprecisein-focusindica-
tion.
Youshouldsetitatcloserthan2m(6.6
ft),
or theprecisein-focusindica-
tionmaynotoccur.
5.ittakesaround0.5sec.toautomaticallyfocusona subjectfromthemaxi-
mumtotheminimumshootingdistance.
SECONDARYPROCEDURESFORAUTOFOCUS
PHOTOGRAPHY
Asshowninthefocusdetectionrangechart(p.17),thelongerthefocallength
ofthelensinuse,thenarroweritsfocusdetectionrange.Toshoota subject
thatisinmotion,youwillneedawideautofocusoperationrangethatcoversthe
distancebetweenyouandthemovingsubject.Ifyousettheprimelens'sdis-
tancescaleatinfinity,theapproachingsubjectmayfallshortoftheminimum
shootingdistanceforthefocusdetectionrangeindicated.
Forexample,whentakinga pictureofa subjectwitha TC-16-mounted300mm
f/2lenswithinarangeof70m(229,7ft)to10m(32.8
ft),
whichistheprimelens's
minimumfocusingdistance,youwon'tbeabletoshootthesubjectifit comes
closerthan35m(114.5ft)ifyou'vesetthedistancescaletoinfinitybecausethe
minimumshootingdistancerequiredforautofocusdetectiontoworkatthis
distanceis35mm
(114.5
ft).
Itisthusbesttoresettheprimelens'sdistancescalebyobservingthefollowing
procedures.
1.
DetachtheprimelensinusefromtheTC-16andattachittotheF3AF/DX-1
assembly.
2.
Focusonthesubjectatitsmaximumshootingdistance;thenlockthis
read-
ingontheprimelens'sdistancescale.(Withthe300mmf/2IF-ED,usethe
lens'sconvenientpresettablefocusingringlockingscrew.)
3.RemovethelensinusefromtheF3AFcamerabodyandinserttheTC-16
betweentheprimelensandtheF3AF/DX-1assembly;thensettheTC-16's
ON/OFFswitchto"ON".
4.
Focusonthesubjectatitsminimumshootingdistance.IfbothLEDin-focus
indicators(X) lightup,thismeansthedistancescalepresetinStep2
enablescontinuousautofocusoperation,ButiftheLEDfocus-impossible
warningindicator(x)*ortheLEDfar-focusindicator(•*)lightsup,this
meansthesubjectiscloserthanthepresetminimumshootingdistance.
So,
inthiscase,resetthedistancescalebyobservingthefollowingproce-
dures.
18