Nikkor H 28mm f3.5

     It's a NIkkor.   I've only taken a few shots with it on my 6D but I don't need to take many to know that its a good lens.   
     My copy has been factory Ai'd and is in excellent condition.   Focus is light yet smooth, just like every other Nikkor from the F era.   Aperture clicks firmly in full stop increments.    Focus throw is a long 1/2 turn which allows for precise focusing from 2 feet to infinity.  It is all metal and glass yet lightweight.   It will balance well on any film or digital body.    Focusing on the 6D was somewhat difficult because of the long focus throw.   Thankfully, it is so sharp that it allows for focus errors.
     Sharp isn't a strong enough word for just how sharp it is.   Yes, it is a tiny bit soft at f3.5, but at f5.6 it is razor sharp.   It's razor sharp corner to corner.   At f3.5 there is strong vignetting and extreme corner blur but there is rarely a reason to shoot a landscape wide open.   Don't misunderstand me.   This lens very usable at f3.5.   
     Distortion is minimal.  
     Bokeh is a bit busy past f3.5 but this lens is made for landscapes and architecture.   Bokeh is not a concern.

     Contrast is excellent at all apertures.

     Color rendition is a tad cool but very consistent.  

     I haven't noticed any fringing but I haven't taken any harshly lit pics.   Bokeh fringing shows as a gradual warm to cool shift.   This is not a concern because it is unlikely this lens will be used for macro work.

     This lens produces excellent b/w images.   Set it at f8 and shoot street pics in b/w.  I think you'll be pleased with the results.