Does anyone have experience with this lens? As part of a new P1 IQ160 system I acquired a P1 150 2.8 AF which is tack sharp throughout the center and central edges of the frame, the 80mm 2.8 LS which shows similar image quality and the 55mm 2.8 LS which is totally different story. I have had 3 copies, all showing the same characteristics:
Very poor central sharpness at f2.8 and f4. Satisfactory to excellent central sharpness at f5.6 and up.
Absolutely horrible (and unusable) central edge sharpness at all apertures until f11 when the edges become marginally acceptable. This involves 30% of the frame on the right and 20% on the left and is not meant to include the corners. Noticeable deterioration begin at f16 due to diffraction.
From my perspective, these characteristics make the lens effectively a 1 f stop piece of glass unsuitable for landscapes and group portraiture unless one is willing to perform major cropping. And if such cropping is done, one has to ask why she/he is using a MF rather than D3x or 1DsIII. Moreover, the necessity of using such a small aperture largely negates the advantage of a leaf shutter mechanism.
I have been told by Digital Transitions and Phase One that this is normal for this lens even though they both have stated that the lens performs on par or better than the 80mm LS which it surely does not. Resolving this issue with the manufacturer and vendor is another issue, but in the meantime I need a wide angle in the 35-55mm range. Can anyone make a suggestion based on personal experience?