5Dmk3 + 100mm Macro f2.8... How's the AF speed?

BLAZING.

It's one of the fastest lenses I've ever used. Some may say it is slow when it hunts; this is because it's a macro. A macro lens has a much greater focus range to cycle through compared to a standard lens. At comparable focus ranges, it is insanely fast to focus.

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If there's typos, you can be sure I used my iPhone.