Eh? Isn't this covered elsewhere? Like in the FED 5b page for instance? Well, yes, sort of, but not to the extent it probably deserves to be discussed.
The Industar 61 L/D is possibly the most highly regarded, and certainly the most often discussed, optic for the Ukrainian Leica copies such as FED and Zorki. There is no doubt that it is a great, sharp lens, well-constructed and even handsome, all assuming of course that you are in posession of a good sample. And once overhauled (see Links below) the I-61 L/D can be quite the jewel in the crown of your kit. But... I must say, having pitted it directly against the other normal lenses in my LTM arsenal, I can't say that it performs even noticeably better than its brothers, the amber coated I-61 or even the oft-neglected I-26M. They are all great performers when working well. And I daresay the LTM Jupiter-8 has a slight edge on them all. Granted, it's nice to have click-stops on your aperture ring!
For the uninitiated, the L in the L/D designation is to indicate that the glass has the element Lanthanum in it, to aid in contrast. The M42 mount version is designated L/Z. I won't swear it's multicoated, since it's not marked as such and might just be very nicely single-coated (though if you hold it under a lamp next to an I-26M and a modern multicoated lens, the argument is pretty clear for MC). Either way, the glass is quite impressive. The L/Z version is definitely multicoated and is marked MC.
The bottom line is this - it's a world-class lens that can be had shipped from Ukraine for less than $30, an even better deal if it comes with a camera attached. Why, I bought a FED 5 just to get one myself....
Not much to say but that mounting is easiest when screwed down to nearest focus, as the rear cam flattens and contacts the rangefinder arm much more squarely (or roundly, rather). No auxiliary viewfinder is necessary as this is a normal lens and covers the field of view of the built-in viewfinder windows of 35mm LTM cameras.
It is a very common occrence that this lens is found with what I would call wonky focusing -- it feels alternately loose and tight throughout the range, or 'slippy'. This is due to the factory grease having congealed into an earwax-like substance that needs to be removed and replaced for your lens to perform optimally. Refer to my special page on cleaning and lubing Industar 26 and 61 lenses, you won't be sorry.
Is it radioactive? WELL IS IT!! Well, no, it's not likely to be unless it was used to photograph the glowing lights of Chernobyl's meltdown from nearby. The Lanthanum with which the glass is impregnated is quite stable or emits such low amounts as to be less than the sunlight that shines on you and your subject, so not to worry. Worry more about the EM radiation from your cel phone...
- My special page devoted to relubing Industar-26 and Industar-61 lenses
- commiecameras.com, a great source for FSU camera and lens info