I'm still exploring the limits of my new 100 f2.8 LIS macro using AI focus rather than the manual "Rocking Focus" method.
This shot was taken using f4.5 with ISO400 for 1/400th sec hand-held.
I was able to watch the eyes of this fly popping in and out of focus as the AI servo kept pace with my movement and I think that the result is more accurately focused and sharper than I could get using the traditional method.
The image is cropped to about 40% of the original as I wanted to use natural light rather than macro flash so had to be further away the normal (I estimate about 2ft)
It really is a quite remarkable lens and Canon have done a super job of matching it to the 7D