Macro image with both Kenko extension tubes.
It's very good at around 1:1; but you can tell from the amount of peaking that it's not quite as good as the 90 macro, or even the FE 2.8/50, at 1:1. Yet around 1:2 it's at least as good. I guess it just isn't optimised for life-size (and obviously the floating elements don't float any further just because you have tubes on.)
I don't think it's a difference that is likely visible in many actual images though (especially as when working with natural light and macro the main determiner of small visible sharpness differences is breeze, vibrations in the ground from cars going past, not having waited for quite long enough after adjusting the rail etc...)
Having said that it's still excellent with tubes, and likely better than most legacy macros..
