35KP-1.8 / 100 (MMZ named after Vavilov). Review of the projection lens adapted in a two-aperture version from the reader Radozhiva.

Material 35KP-1.8 / 100 specially for Radozhiva prepared Rodion Eshmakov (instagram).

Large and versatile Planar, which the Chinese do not yet make.

Large and versatile Planar, which the Chinese do not yet make.

In the 1980s, at the Minsk plant named after I. Vavilov, a diverse line of 35KP cinema projection optics was produced, including classic planars (6 lenses in 4 groups) with focal lengths of 85 and 100 mm with aperture F / 1.8 and split six-lens Planars with focal lengths of 120 (6/6) and 140 (6/5) mm at aperture of F / 1.8. In addition to them, four-lens aplanats of the KO type with focal lengths of 120 (aka - KO-120M) and 140 mm (KO-140M) and the same aperture, which introduces confusion in the notation to this day.

At the same time, completely different lenses with more diverse and progressive optical designs (glued six- and seven-lens variations of planars) were produced at the LOMO and IPZ factories (Izyum, Ukraine) under similar names 35KP / OKP.

In other words, the lenses produced by MMZ are the last of the classic six-lens planars of the 6/4 design produced in the USSR. We can say that these are "overclocked" versions of the predecessor PO50x-1 lenses, but in reality everything is not so simple.

All projection lenses of this series manufactured by MMZ were intended for 35 mm film (as the name suggests) and had a body diameter of 62,5 mm (some LOMO OKP lenses were as much as 82,5 mm in diameter even with a FR of 90 mm), due to which they have sane dimensions of the body and enjoy the attention of amateur photographers.

This article presents the 35KP-1,8 / 100 lens, upgraded for use with modern cameras. A feature of this specimen, in addition to the basic adaptation procedure, is the presence of a second aperture, which serves to control vignetting and the nature of the background blurring of the image.

Specifications:

Optical design - 6 lenses in 6 groups (Planar);
Focal length - 100 mm;
Geometric relative aperture - 1: 1,8 (increased to 1: 1,7 during modernization);
Light transmission coefficient - 0,82;
Landing diameter - 62,5 mm;
Lens block weight - 0,8 kg;
Features - a projection lens, does not have a diaphragm and a focusing mechanism.
Passport of this copy in PDF: passport reference

Design and adaptation

The lens is almost a kilogram aluminum lens unit. Unlike similar optics from other factories, the lenses of MMZ lenses are not rolled into aluminum pancakes. Such a nuance requires more care when assembling and disassembling these lenses: for example, it took a lot of work for me to install a huge front glue in its place. 35KP-1,8 / 120.

Representatives of this line of projection lenses have a much smaller internal diameter of the lens unit body than RO50x-1 and Zh-xx lenses, which is again dictated by the avoidance of bulk assembly. And this introduces huge difficulties associated with the installation of the diaphragm in these lenses: irises with a large aperture are required (in this case, my favorite fourteen-petal 36 mm were enough, but close to each other) and a small outer diameter. I had to grind the aperture barrel from the outside so that it could be installed inside the lens. Most likely, this approach will not work at all for adapting lenses with long focal lengths, since even larger apertures will be required, which cannot be placed inside.

With this lens, I had to sweat to set the internal diaphragm.

With this lens, I had to sweat to set the internal diaphragm.

To compensate for the lens distance during the installation of the diaphragm, it was necessary to order the manufacture of an additional aluminum gasket.

During adaptation, the front slotted nut was replaced by an easily removable ring with a thread for 72 mm filters - it would be nice to wear a polarik on such a lens. A feature of this part was its much larger inner diameter compared to the factory one: this made it possible to increase the working area of ​​the front lens and added another 12% aperture to the lens. In total, we have a 100 / 1.7 lens.

To focus the lens unit, a factory M65-M65 helicoid with a stroke of as much as 55 mm was used - the minimum focusing distance is only 0.4 meters! At a focal length of 100 mm, this provides a scale of ~ 1: 2.

Lens assembly when focusing at infinity.

Lens assembly when focusing at infinity.

The thread pitch is a little too small for such a focal length - from infinity to MDF, you need to make more than one revolution. But such a helicoid can provide high smoothness and focusing accuracy, which is important, for example, for users of SLR cameras.

Lens assembly when focusing on MDF.

Lens assembly when focusing on MDF.

This 35KP has an impressive back focal length. After removing the excess metal from the body behind the rear lens, the cut was more than enough to use a two-aperture layout (it was also enough for compatibility with Nikon cameras). Therefore, the lens was equipped with a second, lens aperture. This option greatly expands the capabilities of the lens: the second aperture is able to improve the contrast of the image (especially on the crop), add a "dramatic vignette" or make the bokeh more swirling.

The second aperture is the secret ingredient for creative ideas.

The second aperture is the secret ingredient for creative ideas.

However, it should be noted that Minsk 35KP lenses with FD> 100 mm have geometric vignetting noticeable in the full frame: the front group of lenses is noticeably larger than the back one, which is done to maintain the 62,5 mm bore diameter and reduce the weight and size parameters. On a full frame, the second aperture works especially effectively at ~ F / 2.5.

Of course, all of the above tuning affected the dimensions and weight of the lens: it is much larger than the adapted PO500-1 and even a similar two-aperture PO501-1. W-53 in comparison with him, quite a baby. However, this 35KP is larger in both aperture and FR.

35KP 100 / 1.7 in a two-aperture version is heavier and larger than the PO500-1 oil refinery in a steel case.

35KP 100 / 1.7 in a two-aperture version is heavier and larger than the PO500-1 oil refinery in a steel case.

Unlike LOMO lenses, the MMZ optics have pink-violet anti-reflection coating. Apparently, the optical scheme did not do without lead glasses: the lens is very yellow in transmission.

View of a round opening of a covered fourteen-blade diaphragm in the light. Yellow tint of lenses is noticeable.

View of a round opening of a covered fourteen-blade diaphragm in the light. Yellow tint of lenses is noticeable.

This lens turned out to be much more difficult to adapt than the usual PO50x-1. However, it is extremely interesting for its extreme optical parameters and the ability to work in a two-aperture version with SLR cameras.

Optical quality

The 35KP 100 / 1.7 with a third stop aperture higher than that of the PO500-1 100/2, turned out to be a better quality lens: the level of aberrations at F / 1.7 is not higher than that of PO501-1 at F / 2. With equal apertures, the Minsk lens looks even better. Although the overall picture at F / 1.7-F / 2.5 is soft due to spherical aberration, a coma is noticeable at the edge of the frame and rather strong longitudinal chromatic aberration - the optical scheme is working at its limit. Need better? Either more lenses, or stick the existing ones.

At F / 2.8, the lens becomes as good as the Zh-53 at F / 2 - and this is not surprising: under these conditions they have equal absolute apertures (35 mm). Strong aberrations of a simple 6/4 planar at ~ F / 2 caused the film industry to abandon the massive OKS1-100-1 100/2 lens in favor of the more compact OKS2-100-1 100 / 2.8. However, for artistic photography, the presence of aperture flavored with aberrations is very useful: with the help of an aperture diaphragm, you can greatly change the nature of the image (the so-called plasticity of the picture) by varying the aberrations. By connecting the second diaphragm to work, you can completely get a picture taken as if with a completely different lens.

Sample image at f / 2 and open second aperture

Sample image at f / 2 and open second aperture

An example of an image at F / 2 and closed the second aperture.

An example of an image at F / 2 and closed the second aperture.

35KP 100 / 1.7 often takes the color rendition into the yellow-green area. Its huge front lens also attracts various hares, rainbows and other artifacts. On the other hand, overall image contrast is generally good. Especially after matte blackening of lens and pre-lens parts according to the results of the first shooting.

Definitely, this lens occupies a worthy place among the classic 6/4 planars: with an absolute aperture larger than that of Helios-40, it provides good image quality even at open aperture with the recognizable good old planar pattern.

Below are sample images taken with a full-frame Sony A7s camera (shooting in RAW, processing in Imaging Edge).

Other movie projection and movie shooting reviews:

  1. RO3-3M 2/50
  2. PO 500-1 F9 CM. 1: 2 P (review from the reader)
  3. 2/92
  4. F = 92 1: 2
  5. ОКП-6-70-1 F=70 1:1,8
  6. LOMO RO501-1 F = 100 1: 2 (+ materials from the reader)
  7. LOMO RO500-1 F = 90 1: 2
  8. 35KP-1,8 / 70
  9. 35KP-1,8 / 75 (review from the reader)
  10. 35KP-1,8 / 85
  11. 35KP-1.8 / 120 (review from the reader)
  12. 35KP-1.8 / 100 (review from the reader)
  13. LOMO P-5 F = 100 1: 2 (review from the reader)
  14. ЛОМО ОКС1-40-1 40/2.5 (review from the reader)
  15. LOMO J-53 F = 75 1: 2 (review from the reader)
  16. Tair-41 50/2 (review from the reader)
  17. KO-120 1: 2,1 120mm
  18. KO-90 1: 1,9 F = 9cm (review from the reader)
  19. KO-120M 1: 1.8 F = 120mm (review from the reader)
  20. KO-120M 120 / 1.8 with a diaphragm and helicoid(review from the reader)
  21. LENKINAP RO500-1 F = 9cm 1: 2 P (review from the reader)
  22. Schneider Super Cinelux 70/2 (review from the reader)

The names of the lenses correspond to their exact spelling on the body.

conclusions

The projection 35KP-1,8 / 100 turned out to be quite a 100 / 1.7. The lens demonstrates the limits of the classic 6/4 optical design. Adapted to a two-aperture version, it allows you to effectively juggle shooting parameters to fit any scene.

You will find more reviews from readers of Radozhiva here.

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Comments: 24, on the topic: 35KP-1.8 / 100 (MMZ named after Vavilov). Review of the projection lens adapted in a two-aperture version from the reader Radozhiva.

  • UstasFritZZZ

    Thanks for your review. It was interesting to read and watch examples!

  • Bukozik

    The bokeh is very pleasant, the picture is still a little rarer and ... autofocus)

    • Rodion

      For such lenses AF, if it can be done, it is only internal: a kilogram of glass and metal cannot be moved by any sane micromotor.

      • koba

        thanks, can you give a link? And another question - as I understood from the photographs of the lens itself, the tail of the M42 is screwed to it. Right? That is, I still need to buy a full-frame mirrorless camera for its full use ...

        • Rodion

          Link: https://www.ebay.com/itm/164550337374
          The lens shank is really M42. I do not know if this means that we need a full-frame UPC, but through an adapter it will fit anywhere. The cut is enough for Nikon without any lenses.
          With a second aperture, you can optimize the lens's crop behavior - and that's a big plus.

          • koba

            that is, it can be put on a Nikon without a lens adapter? This is very interesting, since I have one Nikon camera (D3s), in fact, my working camera ...

            • Rodion

              Yes, this is the main advantage. I made it so that through the usual thin flange M42-Nikon F it rises with infinity without any lenses. I tested this with build NEX-EF + EF-AI + AI-M42. There was even a storekeeper.

  • Molchanov Yuri

    The photos are incredible! The effort and time paid off unambiguously, a great lens turned out! Thanks for your review. and for sharing your ideas. Of course, I would not dare to undertake such a project, but someone with access to a lathe can probably go your way.

    • Rodion

      It is not necessary to decide - I often change optics, so those who wish can sometimes look for something interesting for themselves.

  • B. R. P.

    Very interesting job. Thank you.

  • koba

    great photos. How can you get such a thing?

    • Rodion

      You can buy it on Ebay - it is listed there from my account.

  • Sergei

    Rodion, thanks for the review and the work done. There is such a lens available, but with a simple tubular helicoid. Now I think to put Chinese, threaded. A question for you. If you put a helicoid not 39-90mm, but, for example, 25-55mm, what will I lose, besides increasing the MDF? Thanks in advance for your reply.

    • Rodion

      When using helicoid 25-55, it is better to position it closer to the middle of the lens, i.e. make a shank in the form of a long glass. Otherwise, you will lose balance. Otherwise, no problem.

      • Sergei

        Thanks for the answer. There is no doubt that the helicoid should be placed in the middle due to the weight of the lens unit itself. There is one more question - from which lens did you put the iris diaphragm (front) into it. And can the second diaphragm be set constant (not adjustable)?

        • Rodion

          Iris with Ali too. It is better either not to install the second diaphragm, or to install an adjustable one.

          • Jury

            Hello. And, with what outer diameter did you choose an iris diaphragm for “Ali”? Thank you.

            • Rodion

              This one was like 56.

  • Ilya

    Rodion does not give aperture ring replacement! Not 12% complete nonsense.
    With this lens I got about 1.65 by replacing the inner ring with a larger diameter.

    • Novel

      I love postsov commentators.

      Take the trouble to express your thoughts more clearly. Because the definition of "complete nonsense" suits them better. An increase in the relative aperture from 1.8 to 1.7 means an increase of 12%, everything is correct here.

      • Rodion

        And his inner diaphragm was replaced with an iris, So ...

        • Novel

          Now I don’t understand. Text from the article: “During adaptation, the front slotted nut was replaced with an easily removable ring with a thread for 72 mm filters - it would be quite nice to put on a polarik on such a lens. A feature of this part was its much larger inner diameter compared to the factory one: this made it possible to increase the working area of ​​the front lens and added another 12% aperture to the lens. In total, we have a 100 / 1.7 lens ”. I read it unequivocally - replaced the front nut with a nut of a larger diameter, increased the aperture.

          There is nothing about the inner diaphragm. Was there some kind of washer in the lens unit that artificially reduced the aperture, which you removed? Is the opened iris diaphragm larger than this washer? Or did you just add iris behind the lens unit?

          • Sergei

            all his articles are explained and unsaid in such chunks.

      • Ilya

        And where does the postsovok have you touched on?
        Am I saying something wrong?
        That's right, replacing only the ring by no means gives 12% of the light transmission of the optics.
        Rodion just arrived in time and clarified with the diaphragm. And everything fell into place.

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