As I've mentioned, the Canon EOS M feels great to hold and use, with a great feel, good heft, and a fast interface, working just like the T4i. In fact, as we were briefed about the EOS M, "just like the T4i" was repeated often. Unfortunately, they also said that about the EOS M's Hybrid Autofocus system, introduced just a few months ago on the T4i. We've been waiting for the T4i's main kit lens to arrive, the 18-135mm STM lens, so we haven't completed our review. But the sad truth is that the T4i's Live View mode autofocus is terribly slow. Both the T4i and EOS M have a new sensor with phase-detect sites embedded near the center, as well as contrast-detection autofocus. But the Live View autofocus speed is very slow on the T4i with the 40mm STM lens, averaging more than 1.2 seconds to autofocus in single-point mode, and more than 1.7 seconds in multi-point AF mode. That's just unworkable in a modern mirrorless camera.
While the Olympus E-P1's autofocus was notoriously slow, we really weren't troubled by it at the time, back in 2009. Other reviewers found the E-P1's autofocus frustrating, but we liked the camera's positive points well enough that we could forgive the slower autofocus. It measured about 1.18 seconds to focus and capture a shot. Three years later, the latest models from Olympus, Nikon, Panasonic, and Sony now rival some of the fastest digital SLRs, down in the 0.25-0.17 second lag time range, using both pure contrast-detect and phase-detect systems. Introducing a camera system with a 1.2 to 1.7-second lag time into this market seems unwise.I'll gladly retract all these words, returning to this preview to make all the necessary changes if Canon makes speed improvements over the T4i's Hybrid AF, but I'd be remiss not to report that if the AF system is "just like the T4i" a lot of buyers are going to be frustrated with the EOS M. I only saw a prototype EOS M, but it seemed to perform just as the T4i did with the same lenses. I used the EF-EOS M adapter trying the 40mm STM lens, and it focused about as fast as the 22mm STM kit lens. I'm hoping both cameras' Hybrid AF can be tuned before the EOS M ships in October 2012, because right now only an unaware consumer would put up with the EOS M's slow autofocus, and street
shooters would find the EOS M an exercise in frustration.