A step up from Canon’s cheap-and-cheerful 50mm f/1.8 ("nifty fifty") in terms of build quality, autofocus speed and aperture. The f/1.4 aperture allows the lens to be used in very dim lighting, but it shows better sharpness stopped down to f/2.0 or so. It's a good lens for group portraits or spontaneous indoor pictures, especially when you don’t want to bother everyone with your flash.

Small enough to fit in your pocket, it's nice to carry around "just in case I need a wide aperture". And at a bargain price too.