Supertelephoto zoom lenses have made remarkable strides in recent years, and the kind of image quality that used to be exclusive to the most expensive professional prime models is now available at much more affordable prices and with the added versatility of variable focal lengths. One such example is the Canon RF 100-500mm f/4.5-7.1L IS USM, and this great video shows just how well it performs, even in low light and with teleconverters.