Filming LOMO OKS1-300-1 F=300 1:3.5. Review from Rodion Eshmakov

Material on this lens especially for Radozhiva prepared Rodion Eshmakov.

Adapted OKS1-300-1 next to the Jupiter-12 prototype - Zorkiy BK 35/2.8

Adapted OKS1-300-1 next to the Jupiter-12 prototype - Zorky BK 35 / 2.8


Among the Soviet lenses, fast anastigmats of the "Tair" type, developed by David Samuilovich Volosov, are well known (he is also the author of the schemes "Era","Uran"). Like many other beautiful things in the USSR, these lenses were originally intended for military use as high-aperture optics. for guidance systems, surveillance and intelligence. According to this scheme, one of the best old supertelephotos turned out to be made - Tair-3 300/4.5, a portrait lens now valued by photographers Tair-11 135/2.8, as well as an experienced fluorite telephoto apochromat APO Tair-1 300 / 4.5. Movie lenses of the name "Tair" in the title, as a rule, did not have. Telephoto lenses were developed for 16mm film Tair-41 50/2 (for amateur cinema cameras), OKS2-75-1 75 / 2.8, and for 35 mm film - OKS1-150-1 150 / 2.8, OKS1-200-1 200 / 2.8 and presented in this article OKS1-300-1 300 / 3.5, aperture which is twice as high as that of the mass-produced small-format Tair-3, and a third of a step more than that of a rather rare and high-quality Carl Zeiss Jena Sonnar 4 / 300 and a number professional modern lenses. A good combination of parameters, together with the expectation of "cine quality" make OKS1-300-1 quite an attractive telephoto lens.

Specifications [“Lenses developed at GOI” by A.F. Yakovleva, vol. 1, p. 285]:

Optical design - 4 lenses in 3 groups, "Tair";

Drawing of the optical scheme of the lens.

Drawing of the optical scheme of the lens.

Focal length - 300 mm;
Relative aperture - 1: 3,5;
Aperture limits - 1:3,5 - 1:16;
Aperture - 16 blades, without a preset mechanism;
Frame format - 16×22 mm (calculated), ~9×12 cm (coated);
The back focal segment is 182 mm;
The mass of the lens block is 2 kg;
Features - the aperture scale is marked in T-stops, the lens is rarely found with a focusing mechanism.

Lens construction and adaptation

OKS1-300-1, like other lenses of the OKS series, is produced by LOMO. The year of manufacture of a particular instance is 1978, as indicated by the number on the title ring of the lens. I got only a huge lens block of the lens without a focusing mechanism. It is arranged extremely simply and is a monolithic body stuffed with aluminum frames with rolled lenses and a diaphragm module pancake.

Dimensions of the OKS1-300-1 lens block.

Dimensions of the OKS1-300-1 lens block.

Judging by the initial state, the lens was stored for a long time in some inappropriate place, as a result of which mushrooms settled inside, almost honey mushrooms. Fortunately, the lens block was disassembled without incident and the lenses were gently washed from the fungus, using common sense and years of chemistry as intended: the best way to remove “living” substances from optics is by soaking the lenses in a solution of pancreatin (a complex of digestive enzymes) in a buffer solution with pH ~8 (sodium bicarbonate solution). After water procedures on the optics, only minor traces remained on the enlightenment, which did not scatter light.

The optics sparkle after cleaning from the fungus with almost perfectly clean surfaces.

The optics sparkle after cleaning from the fungus with almost perfectly clean surfaces.

The focusing mechanism was not attached to my lens; from the controls on the body, only the aperture setting ring, marked in T-stops. The minimum number is 4.1. Therefore, the light transmission is 73% - acceptable for a single-coated lens with thick lenses. The transmission spectrum was not investigated - the lens block does not fit into the spectrophotometer. Visually, the light transmission peak seems to be shifted to the yellow-green region - for the so-called. "blue optics" is expected.

The lens turns yellow through the light, like almost all old optics.

The lens turns yellow through the light, like almost all old optics.

The aperture of the lens has a huge size - a light diameter of as much as 76 mm - and has as many as 16 petals, which always ensure an even round shape of the lens pupil. You can't even buy such an iris from the Chinese. Management is carried out smoothly, steplessly.

Perfectly even multi-blade diaphragm is the hallmark of Tair lenses.

Perfectly even multi-blade diaphragm is the hallmark of Tair lenses.

The most difficult thing when adapting such large optical systems is choosing a focusing mechanism. In the case of this Taira, there is simply no chance. One could only try to gut some Tair-33, but I feel sorry for him - it is also a good lens, and the result is not guaranteed to be positive. But the manufacture of a helicoid to order gives the proper result. According to my drawings, one bold and handy Soviet-style turner (for the first time without sarcasm) made a huge helicoid with a large multi-start thread with a giant stroke and pitch, which made it possible to adapt the OKS1-300-1 for medium format cameras with a Pentacon Six mount, which ensures compatibility with the vast majority modern cameras.

A large multi-start helicoid thread, made entirely by hand, is a real art.

A large multi-start helicoid thread, made entirely by hand, is a real art.

The shank of the focusing mechanism is removable - theoretically, you can install another mount. The lens block of the lens can be removed (unscrewed) from the helicoid if necessary.

View of the rear lens element through the focuser shank.

View of the rear lens element through the focuser shank.

The lens turned out to be very large and heavy - about 3 kilograms. Given the huge diameter of the lens block, it is not easy to control this mastodon.

Adapted OKS1-300-1 with Pentacon Six mount.

Adapted OKS1-300-1 with Pentacon Six mount.

It is possible to install a tripod ring on the fixed part of the lens focusing mechanism. You can also fix the lens in the rings of an astronomical mount for astrophotography - here it would definitely show itself well.

However, I am not engaged in astrophotography, but I managed to try out the lens in the usual genres.

Optical properties

On an open aperture, OKS1-300-1, in my opinion, is better than Tair-3, but inferior Carl Zeiss Sonnar 4 / 300 in terms of sharpness due to the higher level of spherochromatic aberrations - it is very high. However, I did not feel the lack of resolution on my camera. Only to facilitate focusing sometimes used aperture T / 5.6. Chromatism practically disappears. But, as practice has shown, only a tripod can be the best solution for facilitating focusing - it was hard for me to focus with my hands. With such a shallow depth of field, the percentage of “micro defocus” is high, as well as blurring from tired trembling hands.

Image contrast is mediocre, at the level of other similar optics. I did not identify critical problems in backlighting. Perhaps this is a consequence of the blackening of the lens, performed during its maintenance.

Color rendition when shooting natural - white balance The camera successfully copes with the peculiarities of the transmission spectrum of the lens.

The OKS1-300-1 has a very smooth, expressive, pleasant bokeh - a characteristic feature of the Tair lenses. Not all "three hundred" can boast of such a blur.

Below are examples of photos taken on a Sony A7s full-frame camera. This time there are no photos through the shift adapter - they could not be taken without a tripod due to the mass of the lens.

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. 16KP-1,4 / 65 (review from the reader)
  9. 35KP-1,8 / 70
  10. 35KP-1,8 / 75 (review from the reader)
  11. 35KP-1,8 / 85
  12. 35KP-1.8 / 120 (review from the reader)
  13. 35KP-1.8 / 100 (review from the reader)
  14. LOMO P-5 F = 100 1: 2 (review from the reader)
  15. ЛОМО ОКС1-40-1 40/2.5 (review from the reader)
  16. LOMO J-53 F = 75 1: 2 (review from the reader)
  17. LOMO OKS1-300-1 F = 300 1: 3.5 (review from the reader)
  18. Tair-41 50/2 (review from the reader)
  19. KO-120 1: 2,1 120mm
  20. KO-90 1: 1,9 F = 9cm (review from the reader)
  21. KO-120M 1: 1.8 F = 120mm (review from the reader)
  22. KO-120M 120 / 1.8 with a diaphragm and helicoid(review from the reader)
  23. LENKINAP RO500-1 F = 9cm 1: 2 P (review from the reader)
  24. Schneider Super Cinelux 70/2 (review from the reader)

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

Conclusions

OKS1-300-1 is a fast telephoto camera with good image quality and a beautiful pattern. The dimensions and weight of the lens are so brutal that it can be recommended either to very strong people or to those who are ready to use a tripod. Optics with such parameters are especially in demand in astrophotography - and here the mega-Tair could show itself well.

You will find more reviews from readers of Radozhiva here... All Rodion reviews in one place here.

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Comments: 3, on the topic: Filming LOMO OKS1-300-1 F=300 1:3.5. Review from Rodion Eshmakov

  • Sergei

    For such an overall telephoto, I advise you to purchase a clamp with a tripod mount (Tripod mount ring) on ​​Aliexpress.
    Should fit a Sigma 120-300 mm/2,8 lens (or similar).
    The inner diameter of the ring is 87 mm.

  • Nikolai (sn797)

    Amazingly beautiful photos. Rodion, thank you for your reviews. You very harmoniously "fit" into Radozhiva!

  • mr.swar

    The Tairov optical scheme is very nice in terms of bokeh, but the residual aberrations of the 3rd order and aberrations of the 5th and 7th orders spoil the picture.
    The introduction of fluorite into the optical scheme made it possible to obtain APO-Tair, but eliminated only part of the aberrations.
    If you recalculate the scheme for modern glasses without fluorite and introduce a DOE without aspherical surfaces, the picture will turn out to be gorgeous.

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