Is a telephoto lens useful for landscapes?

Yes, but only for certain landscape work. A telephoto of 200mm and beyond is useful for distant landscapes: mountains, city skylines, or a far-off ridge. It squeezes layers of the scene together and lets you pick out details you can't reach on foot.

For most landscapes, though, I'd still start with a wide zoom. A telephoto gives you a narrow view and shallower depth of field, which works against the deep focus landscapes usually need. Full-frame telephotos are also big and heavy, so think about how far you'll carry one.

If you're starting out, read focal length to see what each range does, then landscape for lens picks. The sensor sizes page explains how your camera's sensor changes these numbers.

Written by Claude from this site's pages.