In my Guide to Zeiss ZF / ZE Lenses, I have posted an analysis of the Zeiss ZF.2 35mm f/1.4 Distagon in terms of a left/right sharpness symmetry issue which I’ve observed with my test sample, documenting my findings methodically with multiple examples.
The results should not be construed as a commentary on the ZF.2 35/1.4 Distagon in general. I must now consider whether to proceed with testing this particular sample of the ZF.2 35/1.4 Distagon.
In general, imaging systems of all kinds and regardless of cost are problematic today in terms of the ultra high precision required for high resolution digital. Read Making Sharp Images.