Canon Extender RF 2x

The RF 2x teleconverter locks onto my 100-500mm lens seamlessly, and the image quality stays impressively sharp even at 1000mm. It lets me fill the frame with distant birds without carrying a massive prime lens.

I was a bit worried about losing light, but the autofocus still locks on fast enough for birds in flight. The build quality feels solid, and it's nice not having to crop so heavily in post.

I was worried about losing light with the 2x extender, but my 800mm lens still focuses quickly and turns into a 1200mm for bird shots. The extra reach made a huge difference on a distant heron today.