I purchased these two lenses for street photography for use with my Canon R5. They are light - unobtrusive and the image quality is excellent. Highly recommend these lenses for that and general purposes.
When mounting the lens to my Infrared converted EOS-R camera I found I could not attach it to the camera when I had my STC rear filters attached.
I found the reason to be that both these lenses have a protruding circular flange on the lens mount which causes the lens to snag on the locking slider of the filter that stands proud of the filter itself so the lens could not be turned to lock on.
This problem did not appear when using my other RF Lenses as their mount design does not have the flange.
I have gone to circular IR filters attached to the front of the lens.
So there are two slightly different RF lens mounts. Mostly this is not an issue.
To be fair STC do list their rear filters as incompatible with these lenses but I had not bothered to check.
From an Infrared point of view the lenses are great - no hotspots that I could discern and definitely not heavy. AF works as usual.
Care should be taken when buying these lenses if it is your intention to use rear filters.
Highly recommended lenses though. Great image quality at a reasonable price.
I am very satisfied with the lens and also highly recommend it.