The Sigma 24mm f/2.8 lens is an extremely sharp lens. A few of the other people I have talked to who have or have had this lens have all said great things about it. It is very sharp at all aperatures, it is quite small and also very light. It is similar in size and weight to the zuiko 50mm f/1.8 streaching a total of 1.6″.
The lens takes a 52mm filter and the aperature can be set in half stops from 2.8 to 22. Despite the macro label the lens is only capable of, a still comendable, 1:4 maximum reproduction size with a minimum focusing distance of 6.5″.
I purchased the lens off Ebay from a felow from England, which resulted in a painstaking 6 week wait for the lens as I requested ground shipping (which means by boat). I paid about $60 for the lens and it was worth every penny and then some.
Below are a couple of pictures from the lens both at maximum aperature (the B&W) and stopped down a couple of stops (the barn).
Here are is a size comparison of the 24mm large size
Note 11/23/09 – There seems to be some astigmatism going on in the corner’s wide open and stopped down a couple of stops. Not sure what is going on with it, might have knocked an element lose, though it hasn’t taken any hard knocks.