Quote Originally Posted by ddt0725 View Post
Sorry for being so dense and maybe I am getting to analytical about this but could someone explain to me what this means on the difference in the two Canon 100mm macros as far as does it make a difference on use or IQ or does it just have to do with one having IS and the other not ...

100mm IS - Lens Construction: 15 elements in 12 groups
100mm non-IS - Lens Construction: 12 elements in 8 groups
In and of itself it is just how the lens is constructed. The IS version is an L lens, so theoretically much more went in to its design. Really it doesn't tell you it will have better or worse IQ because a lens with the same elements and groups could be improperly made or designed.

Not to make sellers remorse for you, but yes the IQ of the 100mm IS L is better than the 100mm non L's. The L version is a newer lens, and has the new coatings Canon started putting on lenses with the release of the 24L II. The charts show the L version to be better, and the ISO charts show it to be better.

Keep this in mind though; in the real world the difference in IQ is very fractional. Only when you pixel peep the fine detail would you probably notice.

As for your loss of IS, do you still have your macro flash? You could still chase the very small critters.