CROWBAR. Review from the reader Radozhiva

An article about the adaptation of LOMO P-5 F = 100 1: 2 and examples of photos from it, especially for Radozhiva, prepared Vershal Michael.

LOMO P-5 F = 100 1: 2 lens adaptation

LOMO P-5 F = 100 1: 2 lens adaptation

The constant thirst for aperture and the pursuit of artistic bokeh for little money make savvy work to the fullest. That is why interest in old Soviet lenses from cameras, magnifiers, projectors and other optical devices does not run low. For owners of mirrorless mirrors this is a bonanza. For those who "sit" on the DSLR, there are certain restrictions in the case of a small amount of the rear segment of the lenses. For my part, it seemed interesting to me to easily accessible projection lenses, such as, for example, LOMO P-5 100 f / 2. There was a desire to try to adapt them for landing on a Sony Alpha SLT-A37 camera with or without infinity.

What for? To decide whether it's worth bothering at all and investing in the manufacture of more solid homemade products based on projection lens blocks. What's so interesting about these projectors? Excellent "passport" sharpness, not trivial bokeh and high aperture at a penny cost.

A bit of bookkeeping

The first thought, contacting Chinese helicoids, was rejected, because this, I will tell you, is not cheap at all. A Chinese helicoid with the necessary adapters (from 62.5 to M65 + from M65 to M42) is about a hundred dollars.

An option was also considered to choose lenses that could be used as donors, preferably something from the “post-Soviet” one. A really suitable size donor from a mirror meniscus donor with characteristics of 800 f / 8 would cost, well, say, $ 50-70, if you look well.

Both are expensive for the experiment, so my search continued ...

Some theory

Before you start redoing something, you should make sure that the lens you have chosen can in principle “work” on your camera. First: the aspect ratio that will cover the lens. There are different projectors for 35, 16 or 8 mm films - the first one suited me, the second on the crop can give a vignette around the edges, and the third is too small. Second: the rear segment of the lens is the distance from the plane of symmetry of the last lens to the point in space where a sharp image is formed, it is also the focusing of the image at infinity. Roughly speaking, the task is so that the lens unit of the projection projector, in its closest position to the camera mount (or a little further from it), can “finish off” with the formed image to the camera matrix. If the back segment is too small, the image will "hang" somewhere to the matrix, and it is no longer possible to push the lens unit deeper into the camera body. Thus, it will be correct to first find out the rear section of your camera (you can search for the characteristics of both the "carcass" and any lens for your system), and then look for the characteristics of the projector.

LOMO P-5 F = 100 1: 2

In my work I took LOMO P-5 100 f / 2 with the following characteristics:

Frame format: 35 mm.
Lens Type: Aplanat.
Focal length: 100 mm.
Relative aperture: 1:02.
Frame diameter: 62,5 mm.
Lens length: 90 mm.
Back segment: 48 mm.
Light transmission: 90%
Resolution (center / edge): 90/35.

Practical part

On the LOMO P-5 100 f / 2, the rear section is “close to” the Sony A mount (44,5 mm). No locksmith was needed. At the first stage, we used: a Pringles can, an M42-Sony A chip adapter, a piece of thick foam rubber from a technological packaging 10 mm thick, 3M double-sided tape 1 mm thick, strong curved nail scissors and some rubber glue. At the bottom of the can, apply the M42-Sony A adapter as centered as possible, mark the inner hole and carefully cut out the circle with scissors, then make a slot for the bayonet latch pin. We glue the adapter to the bottom of the can with double-sided tape. Next, you need to accurately measure a piece of foam rubber so that it tightly wraps the lens unit with an interference fit. We wrap the lens barrel with foam rubber and carefully insert it into the pot of chips. It turns out a fairly monolithic structure. Finally, cut a hole in the plastic Pringles cover slightly larger than the diameter of the lens unit and close the jar - this solution will fix the foam rubber and prevent it from sliding out together with the lens barrel. Everything! The trial lens with manual (pump) focusing is ready!

LOMO P-5 F = 100 1: 2

However, flaws in the design immediately surfaced. Firstly, the lens unit was reluctant to walk in foam rubber, because in terms of friction this is not an optimal pair, you have to focus with your feet, hands and body, which is not very convenient. In addition, changing the lens to another was fraught with difficulties, you have to take out the lens unit along with the foam rubber, then wrap another lens and shove it back into the jar. Secondly, the bottom of the can is shiny inside, and the walls were, in my case, pink - the color of foam rubber, which is not good, inside the lens should be black. And, thirdly, the lens in this form did not fit on the Sony A37 mount at all - the edge of the can from under the Pringles rested against the beak of the built-in flash. I had to cut off a part of the edge, somewhere in a quarter of a circle, and seal the cut with rubber glue, since in this place the mechanical strength of the already weak bottom of the can was broken, as well as the tightness of the lens.

LOMO P-5 F = 100 1: 2

Further, the homemade product was revised. A circle on the bottom of the can and a rectangle were cut out of dense, but not thick black cardboard in order to twist the tube, which simultaneously separates the lens unit from the foam rubber and “blackens” the inner part of the lens. In addition, since the reaction of people who saw a person with cameras trying to shoot with a can of Pringles was assumed to be ambiguous, it was decided to wrap the body of the can with black duct tape. Thus, the main problems of homemade products, discovered at the first stage, were worked out. The lens unit inside the lens moved much easier (but you had to make sure that it did not fall out), the inside of the lens was made black. The only thing left was to test this design ...

LOMO P-5 F = 100 1: 2

First tests

The expected result for the Aplanat scheme: twisting the background, a sharp center and fast blurring of the corners. Enlightenment is yellow.

LOMO P-5 F = 100 1: 2
LOMO P-5 F = 100 1: 2
LOMO P-5 F = 100 1: 2
LOMO P-5 F = 100 1: 2
LOMO P-5 F = 100 1: 2

Innovation

In fact. Focusing out of a can is a perversion. Good for trial, but absolutely inapplicable in practice! I asked for the idea to insert the projection into the helicoid. One problem is that helicoids of the required diameter cannot be found "for a penny". I had to go for the trick. As donors, it was decided to use ... the now popular souvenir glasses in the form of a lens with a zoom function. The helicoid in them is plastic and with a very small "focusing travel", but nevertheless, it is better than nothing.

The first glass a la Nikon did not fit, with a very decent quality of the helicoid, its diameter in the back did not allow pushing the projector into it, I had to use the purchase as intended - I drink coffee from it at work =)

By the example of this, which has not become a lens, glass can be seen how it is disassembled and how the metal part is twisted from it.

Then a glass of a la Canon with a larger inner diameter of the helicoid was purchased. The projector has thrust itself perfectly into it. The back was cut out as close as possible to the rear lens plane to the bayonet mount, a chip-on adapter with an adapter from the M42 thread to Sony Alpha was mounted on plastic with double-sided tape.

The helicoid in this circle turned out to be quite clumsy. I had to figure out how to build lenses into it and not violate the functionality. Also, the places of friction had to be generously lubricated with Litol. Unfortunately, such a helicoid has no stroke and, as a result, the effective focusing distance is extremely limited - offhand, from 40 to 400 cm, it was not possible to achieve infinity on the DSLR.

Test shots

Hood from RAW with correction BB, contrast and color, resize.

These and 48 more photos... Likewise - flowers, berries, leaves, needles - hands have not yet reached the portrait. The maximum possible applicability in humans is a shoulder portrait and close-up (lips, eyes, etc.).

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 = 90 1: 2 (review from the reader)
  15. LOMO P-5 F = 100 1: 2 (review from the reader)
  16. ЛОМО ОКС1-40-1 40/2.5 (review from the reader)
  17. LOMO J-53 F = 75 1: 2 (review from the reader)
  18. LOMO J-54 F = 85 1: 2 (review from the reader)
  19. LOMO OKS1-300-1 F = 300 1: 3.5 (review from the reader)
  20. Tair-41 50/2 (review from the reader)
  21. KO-120 1: 2,1 120mm
  22. KO-90 1: 1,9 F = 9cm (review from the reader)
  23. KO-120M 1: 1.8 F = 120mm (review from the reader)
  24. KO-120M 120 / 1.8 with a diaphragm and helicoid (review from the reader)
  25. KO-120 1: 2.1 F = 12cm (review from the reader)
  26. LENKINAP RO500-1 F = 9cm 1: 2 P (review from the reader)
  27. Schneider Super Cinelux 70/2 (review from the reader)

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

Conclusions

Of course, a high-quality helicoid cannot replace a plastic mug. However, let me remind you that in fact, for $ 25, you get your hands on a 100 mm focal lens. with a relative aperture of f / 2. Try to find something with the same characteristics for the same money! There are also a couple of millimeters to move the lens unit, but this is unlikely to allow you to reach infinity. However, the drawing, for my taste, the lens has good, beautiful bokeh, narrow depth of field. I really miss the ability to cover the aperture and smoother focusing. In practice, you have to focus with the body, but for “manual maniacs” this is a familiar thing =)

Vershal Mikhail

Reviews from readers of Radozhiva can be found here и here.

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Comments: 95, on the topic: LOMOdel. Review from the reader Radozhiva

  • ... Valery

    5

  • ... Valery

    was like that, transplanted to nikon.

    • Nicholas

      Hello Valery. They offer exactly the same as in your pictures? Is it Minsk? Does it have six lenses? I want to remake myself on Nikon. What is its weight?

  • Maksim

    Projection projectors are a way to get something unusual and original for an inexpensive price.
    - no diaphragm,
    - no focusing,
    - connecting thread / bayonet, also no
    Refinement of such a lens will now cost 350-450 UAH. minimum.
    The process itself is important, as in any hobby.
    Nobody can guarantee what will be the result.
    First of all, it’s a good school to learn a lot and understand a lot,
    This is a hobby that brings a lot of discovery and pleasure with the acquisition of each new lens.
    This is a hobby from which no material return is expected.

  • Veerd

    I bought Vega 12B for 400 p. Remaking quickly, hole 50,5 mm.

    • zengarden

      Why should Vega redo it? it is put through the adapter anywhere ...

      • Veerd

        I needed a helicoid for Leitz Colorplan 90 / 2,5.

  • Konstantin

    I have three projection lenses at 62.5mm, RO-501, RO-500, OKP6-70-1, the focuser made of a medium format macro ring, and a broken adapter KP6 / N, the bayonet cut a macro ring at 42mm, there is an adapter with a 42 / N chip. helicoid two turns about 4 cm, focuses on 501 somewhere from 30 cm to infinity on OKP6-70-1 from 5 cm to infinity.

    • zengarden

      Puma-Nike lenses :)

      • Konstantin

        These are children's bracelets, pleasant to the touch, they don’t slip, a white ring for quick focusing and a blue ring for accurate focusing slightly slides over the lens unit, while yellow ones that are purely decorative cover technological holes.

  • Konstantin

    Almost macro.

  • Konstantin

    Diaphragm overhead made of cardboard as far as there is enough imagination.

  • Konstantin

    I also sawed the lens from the LETI-60m slide projector, the Chinese donor is 135mm. The front lens does not rotate, it focuses from 50 cm to infinity.

  • Konstantin

    With a blend.

  • Konstantin

    With a diaphragm.

  • Konstantin

    Photos from these homemade products can be viewed on my page there from a photo written from which lens was made.http://rasfokus.ru/niosti

  • Konstantin

    PO-501.F2.

  • Konstantin

    SUMMER-60m, diaphragm heart.

  • Ivan

    Chamber Jpeg
    Kenon Mark 2

  • Alexander Hedgehog

    just a maniac))) Well, of course it looks very funny!

  • Vladislav

    Thank you very much for your review! You have removed a whole mountain of complexes and insecurities from my soul! I'm not the most lost DIY, it turns out! My homemade heads for cameras for homemade photo stands (Foba! With such prices ...) adapters and so on are not the fruit of unhealthiness, but just a feature. Hurray, I'm normal, in short! )))

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