You asked

What is the sigma 200mm f 2 dg os sports good for?

The Sigma 200mm f/2 DG OS Sports is a fast, stabilised telephoto prime for full-frame cameras. It's built for indoor sport, where the wide f/2 aperture lets in plenty of light and keeps shutter speeds high. It also works well for portraits, since 200mm gives a flattering, compressed view and the shallow depth of field makes the subject stand out.

It's a specialist lens, not a do-everything one. It's a prime, so you can't zoom, and it's a fixed 200mm, which is less reach than you'd want for birds. If you need that flexibility on a sideline, look at the two Sigma 70-200mm f/2.8 Sports options, or read up on wildlife and sport before you decide.

Written by Claude from this site's pages.

From these pages