From Manufacturer
Currently the lightest and most compact 180mm macro lens on the market, this lens will provide 1:1 magnification, and the two LD elements included in the design of the lens make sure you get the sharpest quality possible. An excellent lens for close-up work in the field. The AF system is not supported by D40 and D60 cameras.
1:1 Magnification
Allows for life-size image on the negative or slide; at a distance of 18.5" (47 cm)
<u>I</U>nternal <u>F</u>ocus
The lens neither extends nor contracts physically when focusing; all moving elements are contained within the lens barrel
Di
Digitally Integrated design lenses are designed to meet the performance characteristics of digital SLR cameras
FEC
Filter Effect Control is designed to rotate the filter to the desired position even with the hood attached. This is accomplished by rotating the FEC ring that in turn rotates the portion of the lens where the filter is mounted