In article , tony cooper
wrote:

Other brands of lenses have the AF-S feature. I have a Tamron AF-S
18/270mm zoom lens that I use. A good walk-about lens with a wide
range, but not as sharp at any setting as a prime lens. ("Prime"
being a non-zoom lens) Sigma makes AF-S lenses, but I haven't heard
good things about Sigma lenses. Tamron makes AF-S lenses for both
Nikon and Canon bodies, so you have to check to see which it is.

nope. only nikon makes af-s lenses.

You are correct. I should have written "AF-S comparable".

the word you want is 'compatible'.

The "AF-S"
is Nikon's designation, and only Nikon's designation. However, other
companies make lenses that work with the D40/D60/D6000 bodies in the
same way that the AF-S lenses work.

that's correct, other than the non-existent d6000.

Actually, it's just the "S" that other brands omit. B&H's specs for
Tamron's AF-S-style lenses describe them as "Piezo drive AF motor".

tamron has two types of internal motors. the piezo version is new and
is what they call their ultrasonic motor and the other motor is a less
expensive and noisier micro-motor.

nikon's acronyms are he
http://imaging.nikon.com/lineup/lens/glossary.htm