Features to loo k for …
Here are some of the things you might like to consider when you’re thinking of going long
Optical stabilisation can be a huge bonus for telephoto shooting (see Know Your Limits, page 77). Dual-mode stabilisers are effective for separating static and panning shots.
Fast and quiet ring-type ultrasonic autofocus is featured on all of the lenses on test. It’s great for tracking both action and wildlife.
A wider available aperture that remains constant throughout the zoom range enables faster shutter speeds at all focal lengths, but the lens will be bigger and heavier.
The weight of the lenses on test ranges from an easily manageable 1.57kg to a whopping 6kg. It’s a big consideration if you’re trekking far or need to shoot handheld.
Zoom range Weather seals
Some lenses have no weather seals, while others have rubber seals on their mounting rings, and a few have additional seals on their operating rings and switches. Unlike with, say, an 18-200mm superzoom lens, the longest available focal length of a telephoto zoom lens is generally more important than its overall zoom range.