An amateur buys a pro lens

This is a lens designed for professional use, and it has all the benefits and drawbacks of Canon's L series of lenses. I bought it to replace the Canon 75-300 f4.0-5.6 lens--I was dissatisfied with the optical quality and lack of image stabilization. Though it took some getting used to, I am now hooked on the quality.

DISLIKES
Don't buy this lens if you're shy or easily embarrassed. It's WHITE and 14 INCHES when fully extended and about 17 INCHES zoomed to 400mm with the lens hood on. This is not a lens for taking casual photos--everyone will look at your and wonder what you're doing. People often comment, saying things like, "I bet you can see Jupiter." It certainly doesn't zoom out that far, but it looks like it does.

Oh, and the lens weighs THREE POUNDS. I had to buy a new camera bag. Even keeping the camera on a strap around my neck is difficult because of the size and weight of the lens. My poor, 20 ounce Elan IIE feels like it's going to break in half when this lens is mounted.

I have few gripes about the lens other than the MASSIVE SIZE. It uses a push-pull zoom, instead of the more typical twisting zoom mechanism. That takes some getting used to, but it's not much of a problem. The zoom mechanism can be locked in place to stop it from sliding in or out accidentally, but the locking mechanism takes two hands to operate. The auto-focus/manual-focus switch is recessed and difficult to move. Did I mention that it costs about $1600?

LIKES
You get what you pay for. For this lens, I paid the high purchase price, and I continue to pay by lugging this beast around. Optical performance is noticeably better than my cheap telephoto zoom. When used with the Canon EF 14X teleconverter, the maximum focal length becomes about 560mm, and optical quality is still excellent.

It's heavy, but thanks to the image stabilization (IS), it can still be used handheld in a variety of different lighting situations. IS can be used in two modes, one for still photos and one for panning shots. I've had successful shots handheld at 400mm and 1/45 sec shutter speed--about 10 times longer than I could use without IS.

It is a professional lens, so it is made of metal, not plastic. That gives it a great feel, and I know it will last. It comes with a removable tripod mount--a necessity, since the weight of the lens makes it impractical to mount your camera to a tripod when this lens is attached. The focusing is fast and accurate, and it focuses close enough to take pictures of small animals like chipmunks and birds.

I thought seriously about returning the lens because of its size, but after one trip to the zoo I knew I couldn't give it back. Even in overcast and shade, the lens was able to take clear, close-up pictures of distant animals. As big as this lens is, it's a lot smaller than a tripod. It's also much smaller than the faster 400mm f/2.8 prime lenses.

SUMMARY
A big, heavy, expensive lens that can take photographs almost no other lens could take.