I bought this lens for a trip to Kenya during December 09. It exceeded my expectations. I had been concerned that it would need a tripod or I would end up with shaky pictures; I neednt have worried. I simply increased the ISO number to 500 and with the light being so good in the game parks I was able to rest it on the roof of the minibus we toured the parks in. I have some cracking pictures of lions that are so close you can count the fly's wings on their noses! The cheetah and leopard pictures are also superb. As an enthusiastic amateur that doesnt use the camera too often(I use a Nikon D90)I was delighted with the results and would recommend this lens without hesitation.