Back in my bolthole, yesterday finally afforded a chance to try the EF 200mm f/2.8 via MC-11 on the a7 IV. It seems to be a close sibling of the 135mm f/2, producing spectacular saturation with beautifully-textured OOF areas.
Still no luck in locating a 1.4X extender III for it, but haven’t given up the search as it could more than suitably replace the much slower RF 100-400mm in situations where lighter (and faster) gear is called for.
This getaway is a bit of an experiment, limiting myself to just four primes (and a zoom, which doesn’t count!) to see what I can get from them. So far, so good!