There is a lot of discussion on this lens. I would like to propose a little test on my copy.
The first series of images (the most boring part) shows perforformance at center and corners on resolution targets. Pse note that chart distance is calibrated for 24x36mm format, so the readings must be divided by 1,27 to obtain absolute line pairs x mm on the 645d 44x33mm format.
Presence of aliasing (moirč) indicate that resolution limit of the sensor has been reached, with stronger aliasing as an indication of stronger contrast of finest details.
CENTER at F3,5
CORNER F3,5
The lens outresolves the sensor, albeit with less energy in the corner.
CENTER at F8
CORNER at F8
very good resolution, with strong contrast center and corner. Resolution maximum between F8 and F11
CENTER at F16
CORNER at F16
At F16 diffraction is prevailing, and resolution is reduced at the level of a 16MP camera.
From a resolution point of view, the FA 35 3,5 is outstanding from full open to F11, with a performance that can be hardly surpassed. In critical shots for moirč, it can be practically eliminated at F13.
INTERIOR EXAMPLE AT F13
A full size jpg of this image can be downloaded from the "view all sizes" page on the Flikr link above.
EXTERIOR EXAMPLE AT F11 ( the usual brick wall)
A full size is also available on Flickr
I apologize for the long post, and hope of not having abused of your patience.
Sergio