auto-focus

Hello friends, As the title indicates, I own an EF 100mm f/2 USM with an issue. The autofocus motor no longer works as it should. Instead of fluidly focusing, it "jumps" (usually about twice) for very incremental focus shifts and sounds more like a stepper motor than an ultrasonic. If you keep...

First off, this isn't a fully objective test (and I'm not sure you can create one without a very sizeable budget), but I found the data interesting enough to share and to hear if others had tested the lenses. I shoot a lot of motorcycle racing, and with picking up the RF100-500 about a month...