Yashinon DS 28mm f2.8

     Yashica made 3 lines of lenses for m42 mount.  DX, DS and DS-M.  DX lenses were single coated and not tack sharp, except for the DX chrome nose.  They had a nice smooth bokeh.  DS lenses were multicoated, sharp and offered a soft bokeh.  DS-M lenses were tack sharp but the bokeh is a little harsh.  I prefer the DS line.  The DS 28mm 2.8 is sharper than a Yashica 28mm f2.8 ML and has better bokeh.  It handles well on the Eos 6D.  Focus dampening is very smooth.  Focus throw is 1/2 turn.  Aperture clicks softly at full stops from f2.8 thru f16.  It is tack sharp in the center at f2.8.  The corners fall off steeply but by f5.6 the whole frame is consistently sharp.  Fringing is not a concern with this lens.  It will flare if pointed into the light but it does not need a lens hood for side lighting.  Contrast is a but high but it is consistent and the lens has decent shadow detail.  Highlight blowout is well controlled.  Color rendition is neutral and saturation is normal.  Distortion is very low  Only minor corrections are needed in architectural shots.  Black and white rendering is excellent.This is a great street lens for full or sub frame cameras.