Canon EF-S 10-22mm f/3.5-4.5 USM SLR Lens for EOS Digital SLRs — $ the RF 24-105mm F4-7.1 IS STM zooms in to cover telephoto scenes and portraits. Canon RF 24-105mm F4-7.1 IS STM Review. Canon EF 24-105mm f/3.5-5.6 IS STM review – Shading. Corner darkening is actually quite dramatic at all apertures when this lens is used at 24mm, but the situation gradually improves through the PiOdt5F.