35/2 Summicron. This is a fine lens in all versions, but is a bit confusing with five optical versions and many variations. Considered sharper than either version of the Summarons. Generally the later the version, the better. All versions have a convenient focusing lever.
* First version 1958-1969 chrome, Two versions, with "eyes" and without. "Eyes" were a viewfinder attachment built into the lens which converted the 50 frame on the M3 to a 35 viewing field. The exact same idea used on the later 135/2.8 Elmarit to give it a larger frameline. The M2 version slightly outnumbers the M3 "eyes" version. 8 elements. Likely to be acquired fogged from original owner, see Fogging. The M3 version focused to 26," the M2 and later versions focused to 28."
* Second version 1969-1973 chrome from 2316001, has a little aperture control lever rather than traditional aperture control ring, 6 elements
* Third version 1973-1979 black only from 2646001, E39 filter or Series VII/hood 6 elements
* Fourth version 1980 to 1998. Sadly discontinued with intro of 35/2 ASPH lens. black and chrome E39 filters. Recognizable by aperture control ring's oval shape. The portion with F/stops is smaller and of a smaller diameter. The gripping portion of the aperture control ring has a larger diameter with serrations. This set up is VERY easy to use. Chrome versions are handsome, but significantly heavier than the black. Earlier lenses have "LEITZ LENS MADE IN CANADA" on filter ring while serial number is on the BACK edge of the aperture control ring. Later variation has "LEICA" on filter ring along with the serial number. A lot of these very fine lenses are on the market now, being traded in on the 35 ASP lenses. Lower prices make them great buys. Sure, the 35ASP is slightly better wide open, but at smaller apertures you will be hard pressed to tell the difference. My own favorite. 7 elements