Maksutov lens - MTO 500mm f/8

Discussion in 'Classic Manual Cameras' started by jdm_von_weinberg, Apr 2, 2013.

  1. MTO 500mm f/8

    Kadlubek Objektiv-Katalog RUS1500

    Focal Length 500mm
    Aperture f/8 (marked, actual transmission is often lower on catadioptric lenses)
    Mass ~1162g (with M39>EOS adapter)
    (see the fascinating story of Imperial mass measurements- the "blob" and the "slug" - at )
    Length ~178 mm long
    Diameter 80±mm. (my measurements).


    Ever had that feeling of being swept along by fate? I've sort of got there by becoming interested in the varieties of Catadioptric (Mirror) lenses.
    I've already posted several reports on these:

    Sigma 600

    Hey, I guess I'm still on a roll, but maybe this and the Spiratone Minitel-S 300mm f/5.6 lens (reported on at ) will slake my thrust for mirror lenses for a while. Hopefully for a very long time. When I mention one of these to my photographer daughter, she just says "Oh, Dad!".

    The Man: Dmitry Dmitrievich Maksutov
    Maksutov also see

    Stalin Prize 1941, 1946

    Order of Lenin (1945,1958)
    The Badge of Honour (1943)
    Grand Prix at the Expo '58 in Brussels - the one that concerns us here - for the MTO lens.

    -not bad for a hereditary noble whose family fought for the Whites in the Civil War. He was also imprisoned during the early 30s and again in 1937 as a Japanese spy. Lots of people simply disappeared in that period.

    His work, when not in prison, was associated with the State Optical Institute in St. Petersburg an organization better known by its acronym, GOI.
    The Lens

    Here is one version of the lens design

  2. This illustration is from Wikimedia Commons ( ). I have modified the reflecting surface to show that it has the same curve as the meniscus lens).
    Maksutov's most well known contribution in the field of optics was made in 1941, when he invented the Maksutov telescope. Like the Schmidt telescope, the Maksutov corrects for spherical aberration by placing a corrector lens in front of the primary mirror. However, where the Schmidt uses an aspheric corrector at the entrance pupil, Maksutov's telescope uses a deeply curved full diameter negative meniscus lens (a "meniscus corrector shell"). He published the design in 1944 in a paper entitled "Новые катадиоптрические менисковые системы" [New catadioptric meniscus systems]. This method was adopted not only by his own laboratory for many of the most important observatories in the Soviet Union, but also internationally. Several commercial telescope-making companies produce Maksutovs, including Celestron, Meade, and Questar.​
    There are other versions of this lens, still identified as Maksutovs, being made and offered for sale today by various specialty producers. The Maksutov type of lens is better known for astronomical work than for cameras.

    My initial interest in the lens came because it was the intersection on the Venn diagram of my interests in old cameras and lens, mirror lenses in particular, and having ended up amassing a larger-than-I'd-like-to admit collection of Spiratone items.

    Here is an early Spiratone ad for when they first imported a version of this lens, made for them especially apparently, with their early(?) version of the T-mount.

  3. My particular example

    I had been peeking at eBay occasionally to see what these were going for, and finally saw a more-or-less bargain BIN offer for one that was said to be ugly cosmetically, but good optically. Besides it also had the original box and filter set.

    When it came, it was obvious when I tried to put an M42>EOS converter on what was described as an M42 mount that it was at least a mm or so larger in diameter, measured with my calipers to 43.88mm in a screw mount. I took off the adapter, whatever it was, and got out an M39 to M42 adapter ring. All I can figure is that I must have tried to put it on upside down, because it started to bind up, so I didn't force it.

    After flailing about for a while, I emailed a Russian dealer who sells these, and he suggested that it really was M39 underneath. So I got out the M39>M42 ring again, and it screwed on easily. Hmm.
    I then attached an M42>EOS mount, and found that the rear diameter of the Maksutov will not fit on the APS-C cameras at all (flash protrusion), and that even the 35mm cameras like my 5Dmkii had too large a forward 'bump' to allow the lens to be mounted. I took off the M42>EOS adapter and found that the lens with a M39>M42 adapter did screw into an M42 Praktica L and allowed infinity focus. However, although I have some TTL Prakticas, I have no working batteries for any of those at home. Sigh. Not wanting to mess around with a separate meter (especially given the world-wide "optimism" of the lens makers for f/stops on the mirror lenses). I dug through my box of film EOS cameras. I put on a M39 direct to EOS adapter and found that it fit with no problem at all on my manual focus film camera with an EOS EF mount -- the Canon EF-M (report at ). Tried the lens on, and it focuses to infinity. Though the screen is a little dim, it is far better than the digital camera viewfinders (I think that if the lens would fit otherwise, LiveView would probably be a good idea here). While all this was going on, the vendor was giving me 14 days to return it if need be, but the elements other than the exterior of the lens were pretty nice, so I was glad to be able to keep it, even if its utility on my digital cameras was not good. I confess I was more interested in this as an historical example anyhow, but I try to shoot everything I get, if at all possible.

    So here is the whole kit in its wooden box - showing the M39 (Zenit, not LTM in flange distance) lens itself, the box and the huge 77mm front filters -- in my kit a 4X natural density filter (important for a lens with only one f/stop-f/8), an OC-14 (OS in cyrillic) red filter, an ??-12 light yellow filter, and a ??-18 deep yellow filter.

  4. There is an inscription on the side of the lens indicating, as noted above, its having won the Grand Prize at Brussels Worlds Fair:

    БРЮССЕЛЬ 1958Г.

    On the bezel front of the lens is MTO 1:8 F=50CM , the red letter П , and the serial number, in my case Nº613xx

    There doesn't seem to be a Soviet postage stamp for the lens or prize, but the closest I could come was the USSR stamp for the Fair itself.

  5. Here is the lens on the Canon EF-M which in some ways is a Classic Manual camera with automatic exposure?
    Well I wouldn't insist on it, but it is incidental here to trying out the lens, which is very clearly in Classic Manual territory.
  6. The Soviet-era 35mm slide film box (E-6) is merely for scale. The film shot was Kodak Gold 400.

    As you can see, the lens black enamel has peeled off to the solid brass here and there, but there is no sign of actual abuse, and the optical system looks clean and clear.

    Since I had done the "view down the street" and the "polyspheroid water tower" for my other posts, I thought for comparison, I would do the same.

    Here is the street scene:

  7. And a 100% crop from the above image scanned at 4000 ppi.
  8. Again, for comparison with the earlier reports, here is my water tower:
  9. and a 100% crop from that image:
  10. I did try to find something more interesting than the water tower.
    Other people go out and get exotic fauna. But somehow, appropriately, all I got was coots (avian coots, that is, Fulica americana). They are not a duck, but a rail.
  11. And another type of old coot, Homo piscator.
  12. We old coots, tend to get along OK, ashore, in a boat, or shooting with a Soviet Maksutov
  13. Soon, I hope, Rick Drawbridge will be along with some of his stunning shots taken with this same lens.
    This is, however, more than enough from me. :)
    In looking for typos, I noticed the odd measurement of the unknown adapter again. I had just finished shooting with a Miranda Sensorex II. I remembered that the Miranda had an odd 44mm internal screw for older preset Miranda lenses. I dug out the strange MTO adapter and it screws into the Miranda body! The lens works fine on the Miranda too.
    The pictures above are just as they came out of the scanner except for adjustment of exposure, etc.
  15. By size it is an old warhorse but it is also nice that you put it through its paces to see the quality of the images it produces. Thanks for the posting.
  16. Great write-up, JDM. Thanks!<br><br>What would your verdict be, comparing it to the 300 mm Minitel and the 180 mm lenses you tested on the same subject?<br><br>It's been years since i did a bit of 'research' on the 'Russentonnen' (the Barrels from Russia - as they were known as in Germany), but i remember that it was advised to slacken the tension on the screws holding the main mirror in both the Rubinar 500 mm and nameless 1000 mm Maksutovs. Overtightening in the factory would deform the mirror, reducing performance. (I duly did, but without testing the lens first, so have never been able to see if it really did make a difference). Maybe this advice would also hold for this older sibling of the family?
  17. Excellent, JDM, you've added immensely to my knowledge of the lens and relieved me of the task of digging around to create a background for a post. I've had time for only a few test shots with my copy, but I'll follow up with a few sample images as soon as I get a chance. It's definitely capable of producing quality images, as your work with the various coot species has demonstrated, though it's not an easy lens to use. I overcame the problem of the Canon protrusion by fitting an adapter and a 10mm extension ring, which gives a focus range of about 4.5 meters to 50 meters, a handy range for the kind of stuff I do.
    My example is in much the same shape as yours, workable but not pretty. In the original post I touched on the possibility of the mysterious adapter being a Miranda, so I'm pleased that you've established this. I post a solitary sample, full-frame 5D.
  18. Good results, JDM. These images would put to shame some of the ones that several bargain brand 500 mm mirror optics could deliver. When my family had a camera shop we saw several examples of 500 mm lenses that ranged from good to awful. A customer once brought in a Samyang lens of this type and it was impossible to reach a sharp focus. Thanks for posting.
  19. What would your verdict be, comparing it to the 300 mm Minitel and the 180 mm lenses you tested on the same subject?​
    Drat. I was hoping no one would ask, but here are the 100% views brought together as much as I can.
    First, the street scene
    180mm lenses first (on Canon 5Dmkii, from RAW):
  20. The Spiratone Minitel-S 300mm vs the MTO 500mm of the watertower.
    Remember that the 300mm is from a 22MP digital image, while the MTO 500mm is on Kodak 400 film on a Canon EF-M:
  21. Here is the 180mm pair for the water tower:
  22. and for the 300 and the 500mm
  23. Given all the uncontrolled variables, film vs. digital, 180mm to 500mm, and others; I find it really hard to say.
    Maybe the Spiratone Minitel-S?
    In more general terms, the little 300mm does look to be one of my best mirror lenses overall; but, as someone always says, it's a sight poorer at 500mm than are the 500mm lenses.
    However, I won't try to show crops, but it is clear that the MTO is really as good as my Reflex-Nikkor 500mm or my Sigma Mirror 600mm lenses, if a great deal more awkward to shoot with, and much dimmer in the viewfinder.
  24. Here for comparison, is a picture of the same water tower from the same spot, but uncropped with a Sigma Mirror 600mm on an APS-C body with a Vivitar (the original company) 2X Extender = 1920mm "equivalent"-- the inset is the same view taken with an Argus C3.
  25. Rick, I'm afraid I didn't connect on your earlier suggestion of the Miranda screw mount, since I had no Miranda until Friday last, when one of my friends gave me one. In researching that....
  26. QG, as for the adjustments- I've seen that too, but I figured this one had made it from sometime between 1958 to 1965 without (or with?) adjustment, so I'm not going to "fix" it.
    As for the cosmetics -- If I weren't such a purist about not modifying lenses, I'd have mine taken down to the brass, polished and lacquered to gleam gold to match my gold Swedish Army "Leica" ;)
    I can't resist it - and the MTO does fit a "Leica" M39 mount; although, as I said, I suspect the flange is different from the RF M39 mount. Imagine the reception at the Leica forum when I pop in with the MTO all shiny and golden on this "rare" Leica*. :)
    *As I've said before it is mostly rare in the sense of lacking the usual Hermann Göring presentation inscriptions.
  27. Very interesting article; far from my reach, though, [in terms of owning one of these]. I came close to buying one from Spiratone in those years! Thanks for the post. sp.
  28. Thanks for all that JDM, just the thing for reading with my morning coffee! Got to love those old Russian tanks and I must admit that I don't have a single mirror lens, must correct that soon! I did see a 500mm Nikkor recently..hmm.
    As for the Gold Leica, surely it wouldn't be too hard to inscribe "to Eva from Adolf" on the baseplate :)
  29. The best optical quality mirror lenses I have are the Reflex-Nikkor 500mm f/8, the Sigma Mirror 600mm f/8, and my new Spiratone Minitel-S 300mm. The Nikkor and the Sigma were both under US$200.
    Obviously people have figured out that the Spiratone 300mm is good, since it goes for a little more--a lot more, if you're not a very careful buyer.
    The Maksutov is very good optically, but is very awkward to use, will not fit many modern cameras with forward bulges above the mount, and is very dark through the finder. Some of the 500mm Spiratones are good, and the latest ones are excellent, but not quite so good as the Nikkor or Sigma. Usually you can buy the Sigma or Nikkor for about the same price anyway.
    Stay away from the modern 500mm 'house brand' mirror lenses. They sell for as low as $100 and are easily worth a fourth of that. Unless you want a "soft focus" 500mm lens, that is.
    The trick on my Leica, is that it has the Swedish 3-crowns on it. Super rare!!!
    The inscription might have to read "from Gustaf V to Victoria" (of Baden). ;)
  30. JDM, thanks for the interesting writing on these lenses. I'm still thinking of getting one. But I'm torn between a Minolta AF 500mm or a Russian 1000mm. The 500mm would probably be more useful, but something about the thought of a 1000mm lens on a crop sensor camera makes me imagine the shots that I could get of things that you just can't get close to. Well, I still have plenty of time before my next splurge on gear, but I definitely want something with more reach and better IQ than the Tamron 200mm-400mm that I currently use.
  31. Siegfried,
    I didn't mean to ignore your implied question (?), but it got lost in other activities. The MTO lens is actually quite good, but it is dim in the viewfinder and monstrous in size, so I don't think I'd actually recommend it to someone who is not hung up on the intersection of "collecting" mirror lenses and old Spiratone gear.

    My two best choices for 500mm and up, are the Reflex-Nikkor 500mm and the Sigma 600mm mirror lens. The later Spiratones 500mm lenses are nearly as good, but cost about the same so I'd go with the Nikkor or Sigma.

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