The Canon 28mm ƒ/2.8 IS USM offers passably good performance for macro work: 0.2x magnification, with a minimum close-focusing distance of 23 cm (9 inches). Build Quality and Handling. Canon uses It's sharp across the frame, it's decently fast, has IS, and is small/light! What's not to love? Well, the EF-S 18-55mm f/3.5-5.6 IS STM is f/3.5 at 23mm. That's only 2/3 of a stop and 1mm difference. Although the 18-55 isn't quite as sharp at that setting as the EF 24mm f/2.8 IS USM is wide open - it's decently close (there's a noticeable Looks like the Canon RF 28mm f/2.8 is a trip down memory lane, then. Shooting at f/2.8 produces somewhat soft images regardless of whether you are looking at the center of the image or the corners. 4ugqH.