Lens Basics and Buying

Lenses shape pictures more than camera bodies do, and this set makes the choices clear. It compares zooms with primes, explains which focal lengths suit which subjects, and sets out a sensible order in which to buy. The 50mm gets particular attention: how to get the most from an inexpensive f/1.8, and whether the dearer f/1.4 and f/1.2 versions justify their prices.