All of my EF and even my EF-S lenses work better on my EOS R5 than they did on my EOS 80D. I even use a 45 year old Minolta lens from a film camera. The EF-S lenses put the R5 into crop mode which has a few less pixels than the EOS 80D. I do not have any RF lenses.
Auto focus seems different to me on mirrorless than on DSLR.
The hawk was on a tree near my house this morning getting the first sun as it began to illuminate the treetops. It was cold here last night, so feathers were a fluffed a little. The EF 2x III extender also works well on the R5. The 1.6x crop of the R5 makes it easier to focus on far away small birds. I set white balance to "daylight". Eye focus found the hawk eye among the branches. I reduced the image to 75% and reduced the JPEG quality to 94 to make it small enough to upload here.
I was not able to use the same auto focus settings on the R5 as on my EOS 80D. The first few days were frustrating as I learned.
This is how the eye looks at 100%.
"Thank you for sharing your experience. The more I read the more I’m leaning towards a mirrorless. Thank you for posting the beautiful red-shouldered hawk photo as well. Birds are my passion."
"The learning curve will be a challenge."
I didn't find that at all going from the 5D mark IV to the R5 and R6, but my setup would probably be considered simplistic by some 🙂
We are birders first, but also flowers and insects. I hope you can swing for the R5 or R6 mark II and hopefully when you get some RF glass it can be L. When I was using the 5D mark IV, I used L glass, but my wife needs light weight, so she uses non L. The RF 100-400 is outstanding on the R6 and she gets really good results with that combo.
Here are some examples of small birds taken with the R5 and EF 100-400mm L II at 40'+/-. If you know warblers, you know most are 3-4" beak to tail. The spider was taken with the same lens at near minimum focus distance, zoomed to 400mm. That is one of the reasons I love the EF 100-400mm L II, its close focusing distance.
Betjothom: "The learning curve will be a challenge."
Naw, don't worry about it. The R5 Advanced User Guide is only 919 pages. All you need to do is memorize every page and you will be up and running in no time. 😊😋
Actually, the transition from DSLRs to mirrorless was less dramatic than I expected. Once you learn Canon's "terminology" for different functions and features, and download PDF copies of the manuals to a computer or tablet allowing keyword searches (and larger print for old, tired eyes) it becomes relatively easy to find how to implement what you're trying to do.
Just be glad you have the advantage of Canon's long evolved, mostly logical menu system. Unlike other mirrorless camera pioneer manufacturers, who shall remain nameless (but who's brand starts with an "S") Canon's placement of feature access in well organized, hierarchical menus makes some sense.
09/26/2023: New firmware updates are available.
08/18/2023: Canon EOS R5 C training series is released.
07/31/2023: New firmware updates are available.
05/31/2023: New firmware updates are available.
05/18/2023: New firmware updates are available.
03/30/2023: New firmware updates are available.