Should I upgrade from the sony a9?

Probably not, unless your shooting has a specific problem the a9 can't solve. The a9 is still a strong sports camera, and used it's a bargain. The Sony a9 II shares the same 24.2-megapixel sensor, so it isn't a real step up on resolution.

The one upgrade I'd act on is the Sony a9 III. It's the first full-frame camera with a global shutter, so it has no rolling-shutter distortion. If that distortion is what's costing you shots of fast subjects, that's a reason to move. Its resolution is only a little higher, at 24.6 megapixels.

If you're not hitting that limit, keep the a9 and put the money into lenses. Your lenses will carry over, since they all share the Sony E mount. For more on buying second-hand, see Buying used.

Written by Claude from this site's pages.