33 facts in comparison Canon EF 24-105mm F/3.5-5.6 IS STM vs Canon EF 24-105mm F/4L IS USM Canon EF 24-105mm F/3.5-5.6 IS STM Canon EF 24-105mm F/4L IS USM Why is Canon EF 24-105mm F/3.5-5.6 IS STM better than Canon EF 24-105mm F/4L IS USM? 12.5% wider aperture at minimum focal length? f/3.5 vs f/4.0 3P-MPix higher sharpness result? Old 24-105mm F/4L still worth it? So it turns out you can get a used 24-105 F/4L IS USM lens for about $320-400. Is it worth it at that price? My current main lens is the EF-S 18-135 F/3.5-5.6 IS nanoUSM. Shooting on a Canon 7dMk2 (though I'd like to upgrade to a C100 mkii at some point). 2qxtgm6.