[Brightcolours]

Sorry, Brightcolours, I don't understand this - can you clarify? I've heard that Sony E mount is similar (or even the same) mechanically as F mount, but there's a smattering of ultra-fast lenses usable on it (including the tailor-made Mitakon and SLRMagic 50mm f/0.95). Do they exhibit the kind of behaviour you've described? (I admit I have no first-hand knowledge on the matter, but people have been adapting old stuff to A7/A7r like crazy over at FredMiranda).

You can't compare SLR lenses with lenses for mirrorless anyway... Lens design is different due to different distance to the film plane.

And then there is the difference between FF and APS-C needed image circle to consider also.

That Mitakon 50mm f0.95 shows to be too narrow too, with quite heavy cats eye-ing expect in the center of the frame.

http://www.sonyalpharumors.com/first-ima...0-95-lens/