If you have a family, you absolutely must get a telephoto zoom lens. This is what I have:
It’s a Nikon 80-200 f/2.8 lens. It’s pro glass, it’s heavy, but man does it take sharp photos:
Most of the other images that I took on my recent trip were shot using that lens as well. It also works great for candid portrait shots:
The only drawback of this lens is its size. It’s not a lot of fun to lug around. The D200 18-200 f/3.5-f/5.6 kit lens is apparently nearly as sharp:
It has image stabilization and is less than half the weight of mine. But I’m very happy with this lens for the time being, so I doubt I’ll switch.
