Originally Posted by
Jack Faller
The 100mm L is the top of the line, but I found the regular 100mm macro lens which is half the price is also quite good. The lowest cost alternative is the EF-S 60 mm ($470 US). Since you are using a 7D with the 1.6 crop factor this provides a magnification ~ 100 mm with a full frame camera. The 60 mm also focuses at 20 cm, which is closer than most others. If you can get that close the 60mm may work for you depending on what you are trying to do.
A possible downside is that the 60 mm will only work on 1.6x sensors, so if you move up to a 1D, you are up the creek.
If you are doing insects that don't like a close approach, a 180 mm could be a better bet.
Nevertheless, since I got the 60mm, I've used it more than the 100mm.-- It mostly depends on how close you can afford to get, but for the 7D, the 60mm works fine.