The lightest 4x telephoto zoom lens in its class ideal for sports portraiture animals etc the telephoto effect can make the picture look compressed or be used to introduce excellent background blur at the 300mm focal length you can fill the frame with a postcard from 15 metres away as this lens features a canon ef electro focus lens mount you can use this lens on a canon full frame camera such as the 1d x 5d mk iii 6d etc and a cropped sensor aps c camera with ef s mount eg