The Canon EF Telephoto lens feature a focal length of 800mm and aperture of f/5.6 which makes it convenient to use. It provides mechanical manual focus and ring-type ultrasonic motor, with inner focus system so it’s a great choice for professional photographers. This Canon EF 800mm f/5.6L IS USM super telephoto lens has 18 elements in 14 groups and it is 461 mm when extended. Its weight is 9.9 pounds.