dourbalistar
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The original APX has a very unique look to it (especially the grain which seems to add detail and crispiness to the image) which I think your photos resemble very closely and that's one of the things I really like about them. Other factors being really good eye for composition and perfect exposure.
It seems that even at MFD this version of the 50 is really sharp.
Do you remember what apperture did you use for the portrait?
I definitely agree about the crispness of Ultrafine eXtreme 400. Before trying this film, I shot through a bulk roll of ORWO N74+. By comparison, not only did ORWO N74+ have more grain, the grain seemed in my opinion to muddy some details. But that's another topic altogether...
I'm not sure if the portrait was exactly at MFD, but you can definitely get in tight with this lens. Don't remember the exact aperture either, but probably either f/2.8 or f/4, taking advantage of the Nikon FM2n's higher shutter speeds in summer evening light.