Yashica ML 50mm f1.7

     Yashica ML lenses are often compared to their big brother, Contax.   Most Yashica ML's were made to a very high standard by Kyocera.   A few were made by Cosina, i.e., the C lineup.  The Kyocera made ML's are of high quality.  Their construction is almost identical to their Contax counterpart.   Image quality is excellent.   They cost much less than their Contax brothers so they are a bargain considering the quality they offer.  
     In some quick testing of the 50mm 1.7, I found it to be tack sharp from f2 in the center.   At f5.6 it is Zeiss sharp.   Contrast is slightly lower than my Planar 50 1.7.   Chromatic aberrations are very similar to the Planar in high contrast scenes.   It's noticeable at 100% view,  but is easily corrected.  Shadow detail is on par with the Planar 50mm 1.7.   Color rendition is very accurate and neutral.     Bokeh is also very similar to the Planar 50mm, smooth and soft wide open and with circular highlights past f5.6.   Flare is sharp and defined when pointed directly into the sun while contrast across the frame remains excellent.  However, a slightly off center framing of the sun reduces flare to unnoticeable levels.  
     The comparison to the Planar is justified, in my opinion.   If you find disappointment in this lens you either have a bad copy or you are expecting an OTUS for the price of a Takumar.  

     Boken fringing tests showed minor color shifting at f1.7.   
     Test pics with the 6D will hopefully be available soon.