You asked

Is the canon rf 600mm f 11 is stm worth buying used?

I think it can be a good used buy, especially since long lenses hold their value and change hands often, so the savings are real. See Wildlife and sport for how I'd weigh reach against cost.

It's an f/11 prime, so it works best in good light and on a body that focuses well. It's stabilised and has autofocus, and on APS-C it frames like 960mm. Pairings I'd look at:

Whatever you buy, budget for a new genuine battery. More tips are on Buying used.

Written by Claude from this site's pages.

From these pages