Hi all, I do not want to sound arrogant but to me when you buy a 4000 euro/$ R5 or 2200 euro/$ R6 or even an R3, why you would buy a lens like that? No offense please but I think that at the end, what makes a great picture beside a good sensor and overall camera is of course a good photographer AND a great lens! The lens is often the key and for such a low price I doubt that lenses like that could compete so well against a Canon RF or a Sigma Art or Laowa Zero…
This has already been answered by others, so I am really just reiterating what others have said, but …
1. Higher price does not necessarily mean better product. I think it’s fair to say that you often get what you pay for, but it’s not guaranteed.
2. What is a better lens depends a lot on exactly what you want to use it for and the circumstances in which you shoot, and there are lots of factors which are relevant, eg different aspects of IQ (sharpness, bokeh, coma, etc), weight, size, AF speed, etc. All gear, even “the best”, involves a set of comprises which may or may not suit your use case.
3. A significant part of what you pay for with an L lens is generally build quality. That generally means larger, heavier and more expensive. Having excellent build quality isn’t equally important to everyone. It is just one of the factors which goes into deciding what lens suits your particular use case.
4. Even if you can say one lens is better than another in some sense, that just begs the questions how much better and is it worth it for your use case? Will anyone actually notice the difference in your photographs? In particular, will anyone notice the difference given the way you plan to display it (social media, large prints, whatever)? If it will it let you shoot in circumstances you couldn’t otherwise shoot in, will you actually start shooting in those circumstances?
Personally, if I had an R5 (or R3 or any other RF mount camera) and I was buying an RF mount 85mm, I would almost certainly get the Samyang 85 f/1.4, although I would also take a look at this Viltrox. The Canon RF 85L lenses may be fantastic lenses optically, but I don’t want a 1kg 85mm prime, let alone at the price they go for. It just doesn’t suit my use case so I wouldn’t use it often. And I have not seen anything which has impressed me about the RF 85 f/2 IS. It’s sharp enough, sure, but the overall IQ, relatively slow maximum aperture, apparently slow AF, and the fact it is not even particularly small or light given it is f/2, mean it doesn’t appeal to me. In fact, I would rather an adapated EF 85 f/1.8 in preference to the RF 85 f/2. YMMV.
So, choose the lens which best suits you and your use case, not just the most expensive one or the one which the internet tells you is “best”.