Despite its focal length, the lens itself is quite compact, just a bit bigger than the Zuiko 50/1.8:
Although my adapter is not fitted with an EMF chip, focusing this lens is not really difficult because of its excellent contrast and reduced DoF (well, i must admit that the Eg-S focusing screen helped a lot). The color rendering is nice, too, with well saturated colors:
The lens shows the signs of some CA when used wide open to picture high contrast scenes (check the top of the can above in the full-res picture), but the overall rendition across the full frame is really good. And the CA is easily removed post-processing the pictures.
Some technical data of the lens:
Name: OM-SYSTEM ZUIKO AUTO-T 100mm 1:2.8
Optical scheme: 5 elements in 5 groups
Diaphragm: f/2.8 to f/22
Minimum focusing distance: 1m
Filters thread: 49mm
If you are interested to see more unprocessed pictures shot with this lens, feel free to browse to this Flickr set on my photostream.