Canon EF 40mm f/2.8 STM reviewThursday January 17 2013 Lens Review
Announced this past June alongside the Canon EOS Rebel T4i DSLR camera, the new Canon EF 40mm f/2.8 STM is an ultra-slim, entry-level pancake lens that uses Canon’s Stepping Motor Technology (STM) to enable extra-quiet continuous autofocus, making it well-suited for video shooting.
At under an inch in thickness and just 4.6 ounces, the tiny Canon EF 40mm f/2.8 is meant to be an unobtrusive all-purpose lens. Given its ability to deliver extremely quiet and smooth continuous AF at a list price of about $200, it makes a perfect companion to video-oriented, entry-level DSLRs such as the Canon EOS Rebel T4i. With a bright f/2.8 aperture and optics that include an aspherical lens element, we’d expect solid image quality for the price, and we put it through its paces at DxO Labs to confirm this.