Sony fe 300mm f 2 8 gm oss vs sony fe 400mm f 2 8 gm oss?

The two are close relatives. Both are Sony E-mount primes for full frame, both are f/2.8, and both are stabilised with autofocus. The difference is reach. The 300mm f/2.8 GM OSS frames like 300mm on full frame and 450mm on APS-C. The 400mm f/2.8 GM OSS gives you 400mm, or 600mm on APS-C.

I'd take the 300mm for sport, larger animals, or any subject where you can get reasonably close. I'd take the 400mm when birds are the subject and you can't get near enough, because that extra 100mm matters most there. The reach guide explains where those focal lengths sit.

Both are fast, so backgrounds will blur nicely. Both are expensive, so it's worth reading about buying used before you pay full price.

Written by Claude from this site's pages.