This lens is a beauty and has been since long on my wishlist. The initial tests indicate some slight defocus on the left side of the image ( at F2.8). But sharp enough overall and especially in the centre. The intended use of this lens is to exploit it’s fast F/Ratio: fast comet imaging with the Nikon D750 / Large Milky Way or nebula complexes with the Nikon D750 and narrow band imaging with the ASI183mm.
Some test shots (unguided)