Seems I just can't win lately. A 75/2 ASPH I got a few weeks ago (and immediately returned) was back focusing by 1" to 1.5" @ 4 ft distance.
Received my brand new M 24/1.4 ASPH yesterday and immediately tested it in the type of conditions where you would use a f/1.4 lens.
For me it is for lower light work ... with f/1.4 being important on the M8 because it can either increase the hand held shutter speed, or lower the ISO compared to the 24/2.8 ASPH.
The very first shots I took exhibited fairly aggressive color fringing on a back-lit subject. My heart sank.
I then methodically ran a side-by-side test of the 24 Lux against the M 24/2.8 ASPH, Nikon 24-70/2.8 @ 32mm (for the same field of view), and Sony/Zeiss 24-70/2.8 @ 32mm.
The M 24/2.8 ASPH and Zeiss zoom showed little to no color fringing. The Nikon was minimal and acceptable ... with the 24 LUX clearly the worst of the lot with an unacceptable level of image degradation due to fringing IMHO. I then tried the lens at f/2, 2.8 and 4, with f/4 still showing CA.
Not what I was expecting from an M ASPH lenses in this stratospheric price range.
Pictures in broad daylight are one thing ... but that isn't what I would buy a f/1.4 lens for. Contrasty lighting and back-lit subjects are inevitable when shooting available light in dimmer ambient conditions.
Caveat: it could well be it is just this copy of the 24/1.4 ASPH ... however, my question would be how the heck could such an expensive lens make it out the door with this sort of CA?
You be the judge. Buyer Beware!