Opticallimits

http://photorumors.com/2015/01/03/yongnu...r-cameras/

For reference, the original's lens construction:

Unfortunately, Yongnuo decided to use the outside construction

of the "EF 50/1.8 II" rather than that of the older "EF 50/1.8" or

that of the original "EF 35/2".

Well, these lenses are way past their patent protection, aren't they ?

The Japanese gang also started by copying the tessars, planars, etc.