Acquiring lenses is the natural next step toward harnessing the power of your Canon. Your camera body likely came with a kit lens, probably the Canon EF-S ... the Canon RF 100-400mm f/5.6-8 ...

[Dan K] had just such a lens from Sigma, but wanted to get it working fully with a camera using the Canon EF lens fitting. Hacking ensued. The lens in question was a Sigma 15-30mm f/3.5-4.5 EX DG ...