In this video, Joe Crescenzi, from CouponPages.Com demonstrates remote autofocus on a Canon EOS T4i, 650D using the new Canon 40mm f/2.8 STM (Pancake) lens and a Pixel Oppilas wireless remote as a trigger.
The video also demonstrates how to use the Polaris light meter to get better exposure and it also lets you hear the sound of the STM auto-focus using the built-in microphone, instead of the Shure SM93 off-camera mic.