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The 1958 world fair in Brussels not only gave us the Atomium, but also Grand Prix Brussels 1958 lenses. (It also gave us the Kometa, KMZ's specially built hypermodern rangefinder camera in the league of Leica's M3, of which two prototypes were taken to Brussels that vanished soon thereafter, but that's a different story.) At least three Russian optics could boast the award: the MIR-1 37mm f/2.8, the Tair-11 133mm f/2.8, and the Tair-3 300mm f/4.5. I don't know if those were the only lenses to receive the Grand Prix, or even if the Grand Prix was a rare honor, but this is all I got from my superficial literature investigation.
The Brussels lenses caught my interest when I found this virtually pristine MIR-1 ('mir' meaning 'peace' or 'world', with 'world' being the preferred interpretation in this context) 37mm f/2.8 in January 2003 at a second hand photo clearout sale for the utterly agreeable price of €5. Assuming it was an L39 lens, I motivated the purchase by saying I was going to compare it to the Jupiter-12, but I found out when I got home that it's really M42. Or maybe not; mine came with some sort of strange adapter that converts it to something like M45. God knows why. (Or maybe you do.)
If I can speculate on the history of this lens (which is always fun), I think the following scenario has a chance. From the serial number 714993, I derive that this lens was constructed in 1971 and sold maybe around '72 or '73 somewhere in Europe, probably Holland. Because M42 was still the popular choice in those days, it's hard to say if this lens was bought for a Zenit, since it's entirely possible that someone bought it to complement his M42 Pentax or Contax. In fact it's rather likely if this lens was really traded in at a photo store, since Zenits have little to no return value. On the other hand, the Dutch being the Dutch, it could well be that someone did buy it for his cheapo Zenit. In any case, Dutchmen walking around with Belgian lenses is somehat ironic to anyone who knows about the good-natured rivalry between the two nations.
Looking this lens up in Princelle, you'll find it under number Zk450 as the MIR-1 that was produced around 1970 at Zagorsk. The same Princelle tells that the optical formula was drawn in 1954 at the Vavilov State Optical Institute. The optical formula can be seen here and shows that this lens has six elements in five groups. Considering that wideangle lenses are always hard to design and that this is a fifty year old design in a thirty year old mount, you can't expect any fireworks. I have to admit that I haven't shot any film with it (as childhood traumas prevent me from shooting M42), but through the viewfinder of a Pentax Spotmatic F, I could ascertain that there's some light barrel distortion, some vignetting at full open, and a sharp center but fuzzy corners. Most of this will probably improve somewhere around f/8, and blah blah blah, more platitudes. In short: it looks nice, but you're not seriously going to use any M42 lens that doesn't say Takumar?
Let's focus on the obligatory "hardware description" part of the article. The first and most striking feature is of course the "Grand Prix Brussels 1958" engraving that adorns the front ring and gives the lens just that extra cachet. By the time this lens was sold, the optical formula was almost twenty years old and the Brussels expo fourteen years in the past, so why the praise? I think for propaganda reasons. "Look, a Western country gave us awards! We're not copycats, we're optical Svengalis of the New Photography! We can do stuff − damn, we have the mofo Vavilov Institute! And don't be somebody's fool and just vote communism, aight?"
The second thing you notice is the finish. Contrary to some other Russian lenses, this one looks firm and solid, almost monolithic. Mechanically it's very sound. The aperture closing ring is so light it feels like it's disengaged, while the focusing ring is smooth, perhaps a tad viscous. Your mileage may vary considerably. The lens is constructed in the tell-tale thick Soviet way, with milled tubes and lots of steel. Enduring, but lacking refinement. You do get the feeling that you're dealing with a heavy industrial product, and as usual with Russian stuff, that's not always a bad connotation to have when photographing.
This MIR-1 version in M42 mount (there were also M39 and Kiev-10 versions, among others) is a semi-automatic aperture lens. Back in the early seventies, Zenits didn't have automatic aperture systems, so to switch quickly from stopped down to full open, this lens has a two-ring system. One ring is the limiter and is set to the aperture value you want. The other is small and smooth and coupled to the aperture. You set the required value with the scale ring, and switch between full open and stopped down by rotating the other ring from one limit point to the other. Very easy, but not as easy as an automatic aperture system, which is why these lenses were anachronisms before they even hit the market. The system worked though, and lots of Zenit photographers used it for years.
Thanks to Pascal from Brussels (!) for this picture of a MIR-1 with a different engraving: all-caps, as opposed to the mixed case on mine.
Thanks to Laurent from Belgium for this picture of a 1966 metallic version.