You asked

Is the nikon af s dx 18 300mm f 3 5 6 3g ed vr good for sports?

It's a usable option for sport, but I wouldn't call it a first choice. The reach is the main point: on APS-C it frames like 27-450mm, so you can get close to a pitch or a track from the stands. The catch is the aperture. It drops to f/6.3 at 300mm, which is dim for fast action, so you'll need bright light or a higher ISO to freeze movement. The stabilisation helps with handheld shots, but it can't stop a moving player.

If you shoot sport seriously, compare it with the Nikon AF-P DX 70-300mm f/4.5-6.3G ED VR, another APS-C telephoto zoom on this site. The wildlife and sport guide covers what to prioritise.

Written by Claude from this site's pages.

From these pages