Olympus 17mm and OMD EM-5
Crutchfield Customer Review (What's this?)
This lens is fantastic. The size, build and speed are very impressive. If you are coming from a DSLR you may think this lens is too small to take seriously but that would be a huge mistake. The image quality and AF speed are unbelievable. Having lots of kids in our family the AF can keep up with them without blur and catches the candid moments that you frequently miss with slower lenses. The OMD and the 17mm are small enough to put in a large coat pocket. Try that with your clunky DSLR. And you will get better images!
Pros: size, speed, build, manual focus snap ring is very handy as well
Cons: I wish it was weatherproof like the OMD body.