Jupiter 9 85mm f2.0 M42
I think the test at this link explains a lot. http://allphotolenses.com/reviews/item/c_9.html and the silver M39 version is Here. Optics: ★★★☆☆ For f 2 to soft. Stopped down from f 4 and above does not show anything special. (only for my copy), poor colors. Ergonomics: ★★★☆☆ No precise sharpening. Pre-selection aperture uncomfortable. Build quality: ★★★★★ Metal, as everything should be. Market value / value of subjective: ★★★☆☆ Less than $ 150 is a very good price. Here are some sample pictures. They were made with Sony Alpha 300. Pictures were taken with aperture F/4 ISO-100 All photos without amendment in graphics programs.