A Review of the Canon RF 70-200mm f/4L IS USM Lens

70-200mm lenses are highly versatile, and though f/2.8 is the professional standard, not everyone needs that wide aperture or wants to spend the money to carry around that sort of bulk. 70-200mm f/4 lenses offer the same focal length range at a more affordable price and in a more portable form, and this great video review takes a look at Canon's mirrorless version, the RF 70-200mm f/4L IS USM.