Is the sigma 100 400mm f 5 6 3 dg dn os contemporary good for wildlife?

Yes, for most wildlife work it's a sensible choice. It's stabilised and autofocuses, and the 100-400mm reach is the range the site's wildlife and sport guide recommends as the usual answer for animals and sport. It mounts on Sony E, L-Mount and Fujifilm X.

Where you shoot matters. On an APS-C body like a Sony a6700 or a Fujifilm X-T5, it frames like 150-600mm on full frame, which gives birds and distant animals more reach. On full frame you get the full 100-400mm, which suits larger animals better.

The main limit is the aperture. At f/5-6.3 it gets darker as you zoom in, so you'll want decent light or a higher ISO for small, distant birds. If you're starting out, the picks section explains why an APS-C body with a 100-400mm-class zoom is a strong value. Buying a used copy can also save a lot, as covered in buying used.

Written by Claude from this site's pages.