A constant f/2.8 aperture across the 17-55mm zoom range, combined with a 3-stop Image Stabilizer, makes this lens a versatile workhorse for low-light shooting on APS-C bodies. Its optical design incorporates two UD and three aspherical elements to deliver sharpness that rivals many L-series lenses, despite lacking weather sealing. This lens is best for event and wedding photographers using Canon crop-sensor DSLRs who need a fast, reliable standard zoom without switching to full-frame.
