Canon Control Ring Mount EF & EF-S to EOS R Lens Adapter

So we have a baseline, I have the EOS R5 and the RP.

The biggest benefit is the sharpness. I have the EF 85 mm 1.4 and I bought that over the EF 85 mm 1.2 because the 1.2 was just so hard to use. The 1.2 was very slow to focus and was so hard to get consistent sharp results. The 1.4 was cheaper, faster to focus, and had IS. But the RF 85 1.2 is better in every way than the EF 85 1.4. In a high speed burst with the EF 85 1.4, I could miss focus for maybe 1 out of 4 shots such as a person walking down a runway. Sometimes as bad as 1 out of 3 or even 1 out of 2 if the lighting conditions were particularly bad. Even with the RF 85 1.2 at 1.2, I would have tack sharp images under the same conditions. It's pretty amazing. And the bokeh is just gorgeous. the 1.4 was no slouch but it's not comparable.

I could say the same with the 35 mm 1.8. corner to corner, it's sharper.

You can say that about the amazing 15-35 mm 2.8.

The RF 100 2.8 I would say it's not worth upgrading to. It's a good lens but not a noticeable upgrade.

The RF 70-200 is a practical upgrade. For one thing, it's super compact and can pack into a bag easily. Plus, you can get it into a sports stadium. For example, Dodgers Stadium has a 6" lens limit. the RF 70-200 is only 5.7 inches long. Once you pass the security, you can extend it to your heart's content.