R7 compatibility with sigma 150-600 c

[FastLensPhoto]

I’m brand new with the Canon side of photography and was looking for a telephoto lens for sports/wildlife photography. I understand i can put a converter from EF to RF but will there be any issues? Are there any better alternatives like the Canon 100-400 IS II USM?

[Tronhard]

Hi and welcome to the forum:

If you are starting from scratch with the R system, I would strongly recommend using native RF lenses for their compatibility for IBIS, superior optics, and focusing.

There is some suggestion that Sigma is going to announce in February the release of some native RF lenses, and I would not be surprised to see either a RF 150-600c or a RF 60-600s lens on that list, but we will have to be patient to see.  In the meantime, Canon have offered a compelling alternative - they have recently released the RF 200-800 which, while not an L lens ( neither are the lenses you mentioned), it is extremely well built, and has brilliant optics.  I am not resident in the USA, so I shall not hazard a suggestion as to specific pricing but, as a newly released unit, it is likely selling at its list price of just under $2kUS.  There is some delay on delivery, but if you want the benefit of this excellent optic, you have time to save up.

[Waddizzle]

If you are building a lens collection for an R series body, then only invest in RF lenses.  There is no guarantee that an EF mount lens is fully compatible with an R series body, especially third party lenses.