Canon's 24-105mm is an excellent zoom lens, going from wide angle to a nice midrange in one lens. The f4 aperture is on the slower end, but it stays consistent no matter what focal range you use, so the shutter speed won't slow down at the higher zoom. The higher aperture number means more of the image will be in focus, so it's an excellent option for landscapes and architecture. This lens also has a nice optical image stabilization system, allowing for shutter speeds up to three stops slower without hand blur. Canon included their quiet autofocus motor, as well as full time manual focus override without having to switch modes. The lens also includes coatings