This is the very first lens I bought with my old film camera, and is very versatile (in fact, this lens remains mounted on my camera most of the time):
At 28mm-35mm, it provides an excellent, wide angle of view, which is handy when you cannot be too far away from the people you are trying to shoot, for example, in a small or crowded room.
At 50mm, it basically becomes a standard lens with the minimum F number of 4.0, which makes it unnecessary to swap out the lens with a standard 50mm prime lens in many cases.
At 100mm, it makes a great portrait lens.
Note however that, with a conversion factor of 1.3 (EOS 1D), the effective focal length range is 36-176mm; with 1.6 (EOS 20D, EOS 30D or Digital Rebel XT), 45-216mm, at which point you lose the wide angle but gain a whopping 200mm telephoto ability.
It also has Image Stabilizer (“IS”; useful in a dim-lit room where shutter speed must be close to 1 second, at which point a hand/body shake will destroy the picture without IS), and a ring-type ultrasonic motor (USM) autofocusing which makes it possible to use full-time manual focus at the same time as autofocusing; for example, you can let autofocus lock roughly on the subject, then manually adjust the focus without having to turn off autofocusing by groping for the autofocus on/off switch.
Comes with a dedicated lens hood, a lens pouch and a matching UV/protective filter. Bought through B&H for $496 including accessories; $330 OBO.
This is the lens some of you know as the “stalker's lens,” which is excellent for capturing subjects far away, with a fantastic background blur. It can also be used for taking pictures of the sun and the moon; [ Atomic Sun ] was, in fact, taken by this lens.
With a conversion factor of 1.3 (EOS 1D), the effective focal length range is 98-390mm; with 1.6 (EOS 20D, EOS 30D or Digital Rebel XT), 120-480mm, at which point it becomes an even greater stalker lens. XD
It also has Image Stabilizer, which is extremely useful minimizing a hand shake while taking a long shot without a tripod.
Comes with a dedicated lens hood, a lens pouch and a matching UV/protective filter. Bought through B&H for $480 including accessories; $350 OBO.