The Canon RF-S 55-210mm F5-7.1 IS STM ($349.99) puts telephoto optics in a stunningly slim and light package, making it an ideal match for Canon's smallest mirrorless cameras. The lens delivers sharp pictures and locks in focus accurately, but it won't add much extra zoom capability to your kit if you already have the RF-S 18-150mm ($499.99). As such, we recommend budgeting more for the RF 100-400mm F5.6-8 IS USM ($649.99) if you're interested in team sports and wildlife; it's a better investment thanks to its longer range and full-frame coverage.A Truly Small Telezoom When it comes to telephoto lenses, the words small and light are often relative because big zooms for full-frame cameras regularly approach 5 pounds. The RF-S 55-210mm meanwhile weighs a mere 9.5 ounces and measures just 3.7 by 2.7 inches (HD). Canon did have to make some compromises along the way though: The lens covers only APS-C image sensors and uses a relatively dim F5-7.1 variable aperture. A bright prime lens...
The RF-S 55-210mm F5-7.1 IS STM is a suitable first telezoom for Canon photographers, but it's worth stepping up to a more premium, longer lens if you have more than a casual interest in telephoto subjects.
Light and compact; 1:3.5 macro focus; Captures sharp detail; Affordable, especially in a kit
All-plastic build; Narrow aperture limits low-light use