Here's my first taste of Russian glass which I bought complete with body 3EHNT (Zenit) ET 5b. This later Helios 58mm f2 lens (model 44M-6) is supposedly the most prominent and all-round best performer compared to it's previous versions, all based on the 6-element 2.0/58mm pre-war Zeiss Biotar design. My copy was probably made around 1991-92 close to the end of its production run. It's a near 90mm medium telephoto film SLR equivalent, when mounted on my NEX-5N. At first I thought the body was plastic because there's not a scratch on it, but on closer inspection it seems to be metal. It's just hardly been used for a 20 year old lens, and possibly why the focusing barrel on this one is also quite stiff. It has a 6 leaf aperture which goes up in half-stop clicks from f2 to f11, then one click from f11 to f16. It's multi-coating has a blue/magenta tint to it, but only from certain angles. Straight-on the glass appears to be absolutely clear without any hint of surface coating... how bizarre! The Helios does not have an external aperture "manual-auto switch/lever" so when the aperture ring is rotated, the aperture blades remain wide open. There is a small pin at the back of the lens that needs to be depressed in order for the aperture ring to work at stopping-down the lens (I'm pushing it in with my pinky finger on the pic above). I've read other folks modifying the Helios internally for this very reason but I don't like the idea of messing about with the innards of any lens. In order to avoid messing with this pin, choose an M42 adaptor that has an internal "flange" (some M42 adapters have them, some don't). This flange will depress the "pin" when the lens is screwed into the adaptor threads. Some sample shots next... .