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AF Micro Adj. 305

vertical line.
As you can see, AF Micro Adjust gives you a very fine way of tuning the
focusing system. If you are testing a zoom lens, it’s most meaningful to
test the lens all the way zoomed in.
Once you have dialed in the correct amount (and verified that it works
properly), you need not do anything else. The camera remembers this
correction and will invoke it again automatically every time you re-attach
this lens. The camera can keep track of corrections for up to 30 different
lenses.
Q: What if I have two Minolta 50mm f/1.4 lenses – will the camera
distinguish between the two?
A: No, it won’t. Each lens has a manufacturer’s model number which is
communicated to the camera body each time it is attached. The camera has
no way to distinguish between two models with the same model number.
Q: What if I have a Sony 85mm f/1.4 and a Minolta 85mm f/1.4?
A: The camera cannot differentiate between two lenses of the same
specifications; even if they were manufactured under different regimes. It
will see both lenses as being the same one.
Q: Will the AF Micro-Adjust feature affect the way I focus manually with
the camera?
A: No, it won’t, as the physical light path from the lens to the sensor
doesn’t change. All this does is put in a slight adjustment for when the
camera autofocuses with your chosen lenses.
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Q: Why is the manual so unclear about how this feature handles 3 party
lenses?
A: Now that’s a good question! And I have a good answer, but it will take
a bit to explain. A long time ago (in a galaxy far, far away), Minolta
introduced their new autofocus lens mount to the world, which had a little
ROM chip embedded inside that would tell the camera what kind of lens it
was, and provide additional information such as focal length range and
maximum and minimum f/stop. The communication protocol was kind of
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proprietary. Minolta said to all the 3 party lens manufacturers of the day,
“Hey, guys, if you want to make lenses that fit our cameras, you have to