Has anyone here used a Yashica ML 21mm F3.5? What do you think of it? I saw an article on the Yashica 21mm vs. Zeiss 21mm lens performance comparison tests in a Japanese book dedicated to Contax. I don't undersatnd all japanese words but they seemed to rate this lens very highly for its sharpness, contrast and light weight. One Yashica internet page also rates it very good.I saw one for sale around $380 used. I thought this might be a more affordable subsitution for the Zeiss 21mm.