V1.02
Thom Hogan’s Complete Guide to the Nikon D300
Page 400
148
18-55mm f/3.5-5.6G ED II DX VR AF-S
150
400mm f/2.8G ED VR AF-S
151
500mm f/4G ED VR AF-S
152
600mm f/4G ED VR AF-S
Lenses with unique ID numbers will be seen by the AF fine
tuning system as “different” lenses, and the parameters for the
lens are displayed in the
AF fine tune
screens. Thus, if you
have an older (#140) and newer (#148) 18-55mm Nikkor, the
system will automatically see them as different, but if you
have two newer 18-55mm Nikkors (both #148) the system
will see them as the same lens.
Fine tuning the autofocus for third party lenses is a hit and
miss proposition. A few lenses are recognized independently
by the camera, most are not. I believe this has to do with the
way the third-party lens makers reverse engineer their
products to work in the Nikon mount
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. Nikkor lenses all
have specific ID numbers, which are passed to the camera
(and recorded in the EXIF data).
Curiously, my D300 is pretty good about reporting focal
length and aperture for a third-party lens
after
I’ve calibrated
it, but displays nothing on the calibration screen.
Enough preamble, let’s get to the nitty gritty.
First off, you need something to focus on. On the CD you’ll
find a test chart (
focus adjustment svga+.tif
) I sometimes use
on my computer’s monitor when I’m in a hurry to calibrate
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:
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Unfortunately, third party makers have a dilemma: they can either use existing
Nikon numbers if their lens mimics the Nikon specifications, or they can invent a
new number. Unfortunately, with the latter, Nikon sometimes doesn’t look for
numbers above a certain value, and the values they do look for might end up getting
taken by a new Nikon lens.
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Super secret hint: I pull the chart up in Photoshop and type the adjustment value
over the chart as I shoot it (e.g. “105mm 10”). Shh. Don’t tell anyone.
