24mm f2 AI/AIS (on Canon!)
Matty W wrote:
and dreadful curvature of field...so bad I'm going to have to assume it's the fault of the misaligned adapter messing with the floating element.
Adapter has nothing to do with field curvature or any other suggested lens error. The lens itself is a complete part working in the right way including floating element.
The lens adapter is only to give the right distance to fill up the smaller Canon body to the lens in comparison to the Nikon body.
The distance from sensor to lens flange for Canon is 44 mm
The distance from sensor to lens flange for Nikon is 46.5 mm
For best Lens quality around 24mm, do get the new Zeiss 25mm/2.0
Zeiss wide open is even better than Nikon's 24mm/1.4 used at f2.0