16 of 17 people found the following review helpful
an excellent lens,
This review is from: Canon EF 300mm f/2.8L IS USM Telephoto Lens for Canon SLR Cameras (Electronics)
This lens is very fast, it can focus very rapidly and follow accurately flying birds, this is the main reason I bought this lens. It excels in every respect, it can be hand held, very sharp even when the aperture is wide open, image stabilization is excellent and it is very fast lens, fast focusing. It can be used to photograph butterflies, dragonflies as I tested it on my 1.6 crop factor camera and found that it can photograph a 15 by 10cm rectangle, thus I can say that it has a maximum magnification of 1:6.7.
This is an expensive lens, so if you think you will use it only occasionally, then I advice you not to buy it, otherwise it worth the price.