ZM-5A 8/500. Review from the reader Radozhiva

Review of the ZM-5A 8/500 mirror-lens telephoto lens and sample photos from it specially for Radozhiva, prepared Rodion Eshmakov.

ZM-5A 8/500

ZM-5A 8/500

ZM-5A refers to super-telephoto mirror lenses. Lenses like this attract today with their huge focal length and compactness. The review presents the Soviet ZM-5A Mirror-Meniscus lens, widely distributed in the secondary market (a review of its lightweight modification ZM-5CA was already, without multilayer enlightenment, lenses with multilayer enlightenment have the prefix MC in the name). Due to the specifics of the lens, a lot of attention is paid to the history of its development in the review.

Lens specifications [taken from here]
Optical design: Maksutov-Cassegrain with field corrector (mirror lens)

ZM-5A 8/500

ZM-5A 8/500

Field of view angle (Kf = 1): 5 degrees
Resolution (center / edge, lin / mm): 40/20
Light transmittance: 0,7
Light scattering coefficient: 0,03
Filter thread: M77 * 0,75 mm
Weight: 1,225 kg
Features: interchangeable A-adapter - allows you to install shanks with M42 / M39 thread or K, N bayonets; constant relative aperture due to lack of iris - F / 8.

History of the development of mirror lenses

The whole family of Soviet mirror-lens lenses (ZLO) was born to the Soviet optician D. D. Maksutov, who in 1941 invented the meniscus scheme. The impetus for this was the attempt to develop a school telescope, which should have good image quality, ease of construction and operation, durability and low cost. The schemes developed by that time (mainly refractor achromat, Newton's reflector) did not meet the specified criteria: refractors were inconvenient to use due to their dimensions and were quite expensive, and their image suffered from chromatism. Newton’s specular telescopes were difficult to operate, since they had an open (and therefore prone to contamination, etc.) pipe and, moreover, required adjustment of the secondary mirror before each observation — it was not rigidly fixed. Hence, the idea was to develop a telescope - compact and not suffering from chromatism, like a reflector, and durable, easy to maintain - like a refractor.

Having investigated the possible options, Maksutov found that the addition of a full-aperture achromatic meniscus makes it possible to correct, to one degree or another, practically all distortions of the spherical main mirror. Moreover, it turned out to be possible to apply a mirror coating on the meniscus - a secondary mirror ("patch" on the front lens), which made it rigid and eliminated the need for adjustment before use.

Applying the invention to the existing Cassegrain mirror scheme, Maksutov developed a number of ZLOs, among which were the TMSh school telescope, MTO lenses (meniscus telephoto lenses), and much more, up to ZL micro lenses. The main advantages of the new lenses are compactness, ease of operation and maintenance, lack of chromatism, low cost (available spherical mirrors are used).

This seems surprising, but the exact same idea with a correcting meniscus was also applied in the Tahir scheme (D.S. Volosov) - one thick meniscus lens corrects almost all achromat-doublet aberrations with an air gap (see Tair-3 diagram, FS-2), which makes Taira probably the simplest anastigmatic lens.

D. D. Maksutov and TMSh - “Maksutov’s school telescope”

D. D. Maksutov and TMSh - “Maksutov’s school telescope”

Design features of ZM-5A

MTO telephoto lenses and newer ZM lenses have an additional element in their circuit - a field corrector. In MTO lenses, this is a negative bonding of two lenses, which “straightens” the lens field and reduces vignetting. In 2M lenses, the component already consists of XNUMX separate lenses and performs the same functions. By removing the corrector, it is possible to improve the image quality in the center of the frame and increase the aperture ratio, however, the vignette will grow and the resolution along the edge will deteriorate. Also a side effect of removing the corrector is the loss of the ability to focus on infinity, which can be fixed by removing the stoppers of the helicoid.

As a rule, Soviet EVLs often have defects caused by improper assembly (there is a known case when Maksutov himself rejected one of the lots of lenses entirely - and what happened when there was no one to reject?) - almost all lenses have a tightened mirror and meniscus. Therefore, it is necessary to disassemble the lens and loosen the locking nuts and screws. Such an operation carried out with an MTO-1000 lens (it is very often used as a telescope), which was not able to show anything other than the Moon, compared it with a modern 90/1250 telescope with a similar scheme - the MTO-1000 began to show stars with dots, details of the atmosphere of Jupiter, etc.

ZM-5A

ZM-5A

Let us return directly to the consideration of the ZM-5A construct. A retractable hood immediately catches your eye, which hides the focus ring when folded. For such a FR, this lens hood is short - for a 500 mm lens, it should be much longer. Even Tair-3A has more. In general, the hood is more likely to interfere, because she copes with her duties unsatisfactorily, but at the same time limits access to the focus ring. The ZM-5CA has no hood.
Also, the ZM-5A has a tripod mount with 1/4 ”and 3/8” threads (the ZM-5CA does not have a tripod mount) - which is very convenient, for example, when using the lens as a telescope for observation.

ZM-5A has a wide focusing ring with a large rotation angle. A feature of the focusing mechanism is the overrun for infinity. Its purpose is related to the thermal stabilization of the lens: when the temperature changes due to thermal expansion, infinity “slides out”. Thermal stabilization is associated with one of the most important rules for using Maksutov's EVA: the lens needs up to 40 minutes at ambient temperature before the image formed by it is normalized. The time span is long due to the large thickness of the meniscus.

Infinity overrun allows full use of the ZM-5A on Nikon cameras with an M42-Nikon lensless adapter.

Unlike its counterparts, the MTO-500, the lens can be used on amateur CZK with a protruding beak of the flash. At least with mine Canon 600D no problems arose.

ZM-5A

ZM-5A

As already noted, the ZM-5A has a replaceable shank, as indicated by the letter “A” in the title. Usually a tail with an M42 thread is mounted on the lens.

It can be noted that the ZM-5A has a successful and reliable construct, but due to poor assembly (there were no Maksutov on them), each lens requires manipulation with loosening the fastening of the overtighted mirror and meniscus.

Optical properties of ZM-5A

ZM-5A has a low aperture with a huge focal length. Because of this, shooting them is a real misery: trembling hands make it difficult to take a sharp shot, and low aperture makes the ISO up. In addition, the lens itself has a low resolution by modern standards. It is simply low due to the becoming noticeable diffraction and residual spherical aberration. Cherry on the cake - low contrast of mirror-lens schemes (a lot of "empty" space - a lot of reflections; it's not for nothing that the coefficient of light scattering is given). Moreover, even on a camera with crop factor 1.6 noticeably serious vignetting.

Moon on the ZM-5A. Crop Post-processing in FS.

Moon on the ZM-5A. Crop Post-processing in FS.

Atmospheric refraction makes a significant contribution to the resulting image - in a bad atmosphere, the quality of photographs of distant objects decreases sharply.

Moon eclipse. Due to the location of the moon directly above the roof of the house, the sharpness is very weak (the effect of atmospheric refraction).

Moon eclipse. Due to the location of the moon directly above the roof of the house, the sharpness is very weak (the effect of atmospheric refraction).

 

"Half" of Venus - 100% crop shot with ZM-5A. So it can be seen in a mediocre amateur telescope, similar to the MTO-1000.

"Half" of Venus - 100% crop shot with ZM-5A. So it can be seen in a mediocre amateur telescope, similar to the MTO-1000.

The ZM-5A has a very, very small depth of field with a small aperture - it is difficult for them to focus through JVI. A lot of photos are getting married.

Due to the presence of central shielding caused by a secondary mirror, the lens has an unusual bokeh - bagels. Not everyone will like it. Subjectively, ZM-5A tries to turn any background into a colorful mess.

Bokeh ZM-5A

Bokeh ZM-5A

The advantage of the lens is a small MDF - only 4 m. For such a FR, this is an achievement. This allows you to shoot a pseudo-macro with this lens, getting frames with a very specific picture. Also, ZM-5A does not suffer from chromatism, unlike lens lenses.

As a result, despite the noted advantages of the lens, the chances of getting a sensible photo on it, say, on a cloudy day, tend to zero. The lens definitely requires a solid tripod for shooting. My attempts to use it for handheld shooting, for photo hunting turned out to be a failure - what the pictures say.

It turned out that the ZM-5A is of much greater interest when used as a telescope. At the same time, small increases of the order of 20-50 times are permissible, which allows us to consider the disks of large (apparently angular size) planets (Jupiter, Saturn, Venus), “split” some binary stars (Lira epsilon is divided into 2 stars [each of them is also double , which can already be seen in more advanced instruments] at 50x - this indicates sufficient optical quality for an astroinstrument), observe large extended nebulae and bright objects of deep space. For use as a telescope, you only need to screw on the M42 macro ring, in which the eyepiece is fixed (for example, from the MBS microscope - affordable and high-quality eyepieces)

Observations in ZM-5A mounted on a heavy tripod Moskinap

Observations in ZM-5A mounted on a heavy tripod Moskinap

For astrophotography, the ZM-5A looks seemingly attractive, but it is not suitable - too small aperture.

conclusions

Everyone should try the ZM-5A - this is a very inexpensive lens that allows you to feel the super-range. But, unfortunately, it is not worth laying special hopes on him - the image quality is far from what modern cameras require. I would not recommend this lens as the main super telephoto lens. Where the best option for a similar price is the Soviet Tair-3 or even autofocus telezoom. Meanwhile, the ZM-5A is quite suitable for the needs of astronomy - like a small telescope for visual observations.

You will find more reviews from readers of Radozhiva here.

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Comments: 61, on the topic: ZM-5A 8/500. Review from the reader Radozhiva

  • NE

    The author has great respect for the professional review. With great respect and best wishes!

  • Ilyas

    Sa version was popol and misery
    Perhaps Normal is not bad

  • Sergei

    “… The advantage of the lens is its small MDF - only 4 m. For such a lens, this is an achievement. ... "
    IMHO, this is not an achievement at all :). The same Tamron SP 500/8 55BB MDF is 1,7 m.

    • another novel

      Of course, the author exaggerated here, this is the most common MDF. But Tamron 55BB was launched in 1983, and it is more correct to compare it with the peer “Rubinar 500/8”, which has an MDF of 2,2 m and a scale of 1: 4.

  • Igor

    Glass purely film on a film might even have been nothing at that time, and on a figure it’s not even soap at all, but nothing at all.

    • Rodion

      I did not see the film for 1600 units.

      • another novel

        Rodion, used to be sold (about 15 years ago):

        • Rodion

          We agree that it gives a worse picture than the matrix of at least my six hundred on 1600?

          • another novel

            I did not specifically compare the Canon 600d to 1600 and the Konica Centuria Super 1600, but the issue of comparing film sharpness and numbers can be debated for a long time.
            I still keep my videos in the freezer for a responsible occasion :-) (I don't even know what kind of case it might be) because I remember that it was relatively expensive. And for the sake of such a test, ahahah, I won't click it. This series of Koniki, which appeared at the end of the film era, is a masterpiece of film production, and without the expensive “professional” price tag.
            In general, the figure surpassed the film in sharpness, sometimes it is incomparable, but another thing is that the figure is free, and the film is a frame of 0,1 + $.

            • Rodion

              . it's not even a matter of film / digital resolution. I'm talking about the grain / noise level. I've heard very dark rumors about sensitive film ...

    • another novel

      He has no sharpness in details, but at the same time he is surprisingly contrasting and pleasant.
      If you do not look for super sharpness in it, then it is just perfect! It’s just a fairy tale for me! It was not for nothing that the USSR put the quality mark on him.
      It is not worth sprinkling a picture from it, and if the photo is not for a magazine spread, but just for illustration 10x15, it will do. Of course, I mean a working ZM-5a.
      Well, you need to be able to shoot like that too!

      • Rodion

        It is contrasted only because each photo was drawn from RAW. Alas.

        • another novel

          All SLR lenses are generally non-contrasting. Usually the picture is too ... faded. And from my "ZM-5a" I sometimes do not even pull the contrast. In general, the contrast with the ZM-5a is comparable to that of a conventional lens, which is why I wrote “surprisingly contrasting”.
          In general, with zl.o. you can and should increase the contrast, while the picture improves radically!

          • Rodion

            Lots of space, two mirrors, ineffective “carrot” - high light scattering.

            • Rodion

              * empty

  • Oleksandr

    Very informative, thanks!

  • Victor

    Not a bad lens. The problem is exclusively for those who do not have good focusing skills with their hands. You can also refer to the strong "stretching" of the focusing scale ... but this is inherent in all z / l telephoto cameras.

    • Rodion

      He's already very highly specialized. Would be suitable for a camera with an FF matrix and low pixel density - less resolution requirements and higher working ISO.

    • another novel

      Victor - All evil have different distance scales! In "ZM-5a" it is the MOST optimal, and all evil in this should be equal to "ZM-5a"!
      Rodion - I agree. The cameras just have a switch to a smaller image size - I set the minimum size - the sharpness does not fall :-), but the noise at high ISO is greatly reduced!

  • Andrei

    and for this UG ask $ 90-180

    • Rodion

      I bought this one, exchanging for Helios-44M-7 (which cost me ~ 1000r). Yes, and on sale for 2-3 tr. full of them. You just need to be able to search.

  • zengarden

    A wonderful review, as usual, Rodion :) the lens is interesting, but too specific, not for everybody. Once it was in demand due to the large focal length and lack of aberrations; but at present, modern televisions are doing it in almost all respects. I thought to buy myself such a cheap thing, but did not have time (yes, to shoot the moon, no matter how trivial); and then compared with his dark fuj-zoom 50-230 / 4.5-6.7, so he showed the moon no worse, although the focal length is half as much.
    In general, a lens for lovers of experiments and other enthusiasts :)

  • another novel

    Please tell me the dimensions of its front cover. And then I lost, I have to order from a turner :-(. Diameters: external knurled, and internal protrusion with a thread. "Length" of the knurled part, and full.

    • Rodion

      I have not had this lens for a year and a half. The review was written from memory.
      I think the cover can be bought on Ali - diameter 77 mm.

      • another novel

        My other lenses also have 77mm caps (and filters), but plastic. But I want it to be authentic and condo :-). And besides, for the big evil with which the "pan-shaped" go, I want to carve the screw-in lid in the same way.

  • another novel

    The dimensions in the drawing are indicated by letters. If the drawing is not correct, correct:

    • Rodion

      Try contacting the owners of the Lens Club. They will help there. I don’t have a lens anymore.

      • another novel

        Thank you on this, but I think someone with a caliper and ZM-5a will respond)

    • Alexey

      Good afternoon. If you are still interested in sizes, then I intended these:

      • another novel

        Oh Santa Maria! Grazio Millet! Mercy Boku!

        • Alexey

          Yes, not at all)
          I forgot to add - there the corrugation is done along the outer contour, a step of 1 mm seems to be.

      • another novel

        While I was considering your drawing, I woke up the desire to draw it myself. In order not to lose deflate:

  • Kirill

    I advise you to pay attention to the Samyang 500 F6.3 - it gives noticeably better resolution and sharpness than the ZM-5A. I took both for the test. And his aperture is excellent for 500mm - I didn't have any suffering. As for me, I shoot from my hands like that without smearing and without a stub Sigma 50-500 at aperture F16-F20, staying within ISO 400-500 on a clear day

    • Rodion

      For me, 500 mm is superfluous, 300 m Tair-3A is enough for me. I'm very pleased with him.

    • another novel

      Various Reviews on Samyang 500/8 and 800/8 - together they say that a rare muck. Very literate people told and showed by their example how to adjust them - it's a dreary long time and not everyone will succeed without breaking this ... thing.
      They also showed the final photos - the ideal has not been achieved!
      In general, Samyang is a complete ... disappointment.
      And you say a good lens, yes ?! Photos and reviews of course not? How much does Samyang pay you for advertising on forums?

      • Kirill

        Samyang 500 F8 YES GOOD! DO NOT DISPUTE or prove

        He expressed a personal opinion since used 800 \ 8, 500 \ 6.3, 500 \ 8, ZM-5A. If you do not take Samyang 500 \ 8 into account, the worst mover I took was the obsolete shovel. And for the Samyangs, the scheme on computers is calculated and, accordingly, the percentage of marriage is almost excluded. And 800 \ 8 is slightly less sharp than 500 \ 6.3, but you can shoot and squeeze good photos. Much more depends on the shooting technique and the camera itself. On the wretched old crop-kenon where the sharpness and details are squeezed from the matrix itself, there will be one thing, and on FF Nikon there will generally be a different level of quality

  • another novel

    By the way, under the article there are clearly not enough links grouped in one place to other reviews of mirror lenses on radojuva.com:
    ZM-5sa https://radojuva.com/2012/03/obzor-ms-3m-5sa-f8-500mm
    MTO-11 10/1000 https://radojuva.com/2012/08/obzor-ms-mto-11-10-1000/
    Rubinar 5,6 / 500 http://https://radojuva.com/2017/04/ms-mc-rubinar-5-6-500-macro/
    "Samyang 8.0 / 500" https://radojuva.com/2016/03/samyang-mc-mirror-lens-500mm/

  • anonym

    My copy of the MTO-1000A shows contrast much worse than a simple MTO-1000, while the stars seem to show dots and, if a little defocus, in the right circles. Do not tell me where you can see a detailed description with pictures, how to loosen the meniscus on the MTO-1000A? I found this only for the mirror, weakened, it did not give an improvement. It's not a mirror or a meniscus; is it possible that the inner surface is blackened worse?

    • Rodion

      Met manuals when searching in google on astroforum. Look for it.

  • cricket

    Can you tell me if there are any options for improving the contrast? My MTO-1000A shows a contrast much worse than a simple MTO-1000, I can’t understand what this may be connected with. At the same time, the stars show like dots and, if slightly defocused, in regular circles. The mirror mount has weakened, there are no improvements. I haven’t reached the meniscus, should I go there or is it not the meniscus and the mirror, maybe the insides are darkened worse?

    • another novel

      You did everything right.
      It is elementary to loosen the meniscus clamp (in 1000A it is double) - it is clamped in front by a nut. Unscrew a little so that the meniscus dangles, and then tighten until they stop dangling, but without tension, not very much. At the same time, tap on the sides so that the lens sits exactly in the center.
      Before unscrewing, I advise you to put a cardboard cut out on the entire diameter of the meniscus so that whatever happens (scratches). (And this precaution is not superfluous.)
      Yes, all the evil of such generations has the opportunity, not by optical means, to greatly increase the contrast, but all evil, even without it, has a reduced contrast.
      What exactly with your lens without seeing it is difficult to say.
      I add that the clamping of the meniscus affects the sharpness and shape of the stars, and if you have them round then most likely it is not in it. Meniscus has little effect on contrast.
      But do you see a secondary mirror (mirror) circle on the meniscus?

      • cricket

        thanks for the advice. I'll try just in case with the meniscus. The mirror circle is like a whole, in general the lens is unused, everything looks like new

        • Rodion

          The meniscus really needs to be loosened. It is truly dual in the MTO-1000 (to accelerate thermal stabilization and reduce weight).

        • another novel

          Did you look at the mirror when you took it apart? Take a cotton swab and gently swipe over it - is there any plaque?
          And about the menisci and the rest of the lenses, see if they're clean.

        • Rodion

          In general, checking a lens like the ZM-5A or MTO-1000 should be something like this:
          -Take the lens, put on a tripod
          -Take an eyepiece with FR = 10 mm (microscopes have the indicated magnification, the FR can be extracted from it by dividing 250 by the indicated magnification), look at a bright star (Vega, Arcturus ...) through the lens.
          -If the diffraction pattern is good, everything is in order. If it is not there - you have to think, de jamb.

          • cricket

            Thanks. Somewhere lay the ocular nozzle Tourist, I'll try with it. And what is the advantage of searching for a diffraction pattern through an eyepiece over photographing the same star with a digital camera?
            Another question, is the double meniscus glued there? There is no problem of swapping one part relative to another?

            • Rodion

              The eye is better, because the magnification is large, but there are no limitations associated with the camera matrix (shake, noise, etc.).
              The meniscus in MTO-1000 from two separate lenses. The shift problem will not arise.

            • another novel

              By and large, it is better, of course, to take a picture;) And do not be afraid of noises and movements.
              Make an artificial star, turn it on. Move your MTO-1000 8m or further away, place it on a tripod, or otherwise fix it, but it won't be easy to aim. Of course, it is better to take pictures with a cable, especially since it is inexpensive. Use the lowest ISO (usually 100). Exposure 30 sec. But take a few takes, and also take pictures with different exposures. At a shutter speed of 1 min, all rings (if any) will appear, and at 5 sec the shape of the disc will be clearly visible. On 1 - its "top". Photograph a star in focus and out of focus before and after focus.
              With "Tourist-FL" - less hassle, but worse in that you do not consider the diffraction pattern due to turbulence. And it will be even more difficult. Just see if there are rings or not. And not in all weather conditions this can be done.

            • another novel

              But actually, you almost certainly have a dirty mirror. Clean it first, otherwise the diffraction pattern will also be in the soap.

              There are many materials on how to wash it, you will need distilled water and a Fairy type detergent, cotton swabs and cotton wool, or tampons, better sterile. And alcohol or pure gasoline (in bottles). Soak, then rinse with water from the tap, then with alcohol, then with distilled, and dry on its side.

              But I recommend Lenzpen. True, you will need additional "charcoal", because your mirror is probably very dirty. Look for a carbon black method for cleaning the optics, the new Lenzpen will only be enough for a small part of the mirror.

              • Rodion

                Galosh, pear and cotton swabs - our everything.

  • Wladyslaw

    Hello! My dear readers of this wonderful forum, Russians and Ukrainians and all other respected peoples!
    I bought the MTO-500A lens yesterday (my experience as a photographer since 1978, including from 1994-1995, because I shoot architecture, streets and airports on request), but compared to my standard super-telephoto camera Sony AF 100 -300, MTO-500A - the king, with your special tasks. I shoot birds (from 20 to 500 m) and aircraft on approach / takeoff (from 200 to 7000 m). I myself am a former aviator, I flew all over the world as an aircraft manager (FROM TU-134b to Falcon 900-DX), incl. AK representative in different countries.
    So, I recommend this lens for unprofessional experiments, although you can catch quite a professional shot on it.

  • Wladyslaw

    The famous “Bagels” in the background still need to be very hard to catch. They are not in my pictures for infinity. Try, my dear friends, photographed)))

  • Katherine

    If anyone finds it useful - Nikon D5100 with M42 becomes without question. The flash does not interfere - there is still 2-3 mm before it.
    I use it together with the Sigma 70-300 (with stabilization and autofocus) - the difference in the pictures is significant, but there are no particular complaints about the juice worker.

    • Katherine

      * shovel

  • Dmitriy

    Thanks to the author for a detailed review!

  • Igor

    Hello, and please tell you which one is more like the older 5a or his younger brother 5sa. the younger lens is 7 mm smaller (measured).

    • US6IBD

      I do not think that they have significant differences from each other. Regardless of the diameter of the lens F = 8. Differ in weight and enlightenment. But still, they are not suitable for backlight.
      I use ZM-6A. His aperture is 6,3 (!). The diameter of the lenses is even larger, and so is the weight.
      It has (like the ZM-5) one feature - a noticeable focusing deviation from the temperature even at infinity, along which it has a "overrun", especially in winter, naturally. Affected by the change in geometric dimensions. In the cold, the lens must be kept for a while after exposure.

  • Igor

    Hello. Maybe someone will be interested. From 5a built a pipe. I screwed on it a M42 2x teleconverter, a German and a cut off head with a prism from a small metallographic microscope. Eyepiece WF10x. Without a converter, the working length is short, the prism does not melt. It turned out pretty well.

  • Vvs

    I add that it is better to shoot on it with a tripod and with a preliminary lift of the mirror.
    I saw pictures on MT500 and Fujifilm on Picabu, I liked them

  • Maksim

    Thank you very much for a very detailed review! Everything became much clearer. And then I bought an inexpensive MTO-500A and I just can't get out of sharpness. I would not even think about thermal stabilization and a tightened meniscus. We will experiment, disassemble, find out. ))) Thanks!

  • Vladimir

    Good afternoon, I stumbled upon such a problem, I purchased a 77 mm light filter, and its thread is so short that it is not captured by the threads of this lens. Therefore, the question is, are there any extensions or threaded hoods for m77, with a sufficiently long external thread and an internal thread close to the edge?

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