[miro]

  https://www.lenstip.com/lenses_reviews.html


https://www.flickr.com/photos/124690178@N08/

Thanks for sharing
Sigma did it in the past too. e.g. Sigma 120-300/2,8 comes in my  mind.
http://www.opticallimits.com/canon_eos_ff/629-sigma120300f28oseos?start=1

As always, the competition is good for end user. As refference look at the prices of NIkon/Canon fixed focal 400+mm