Helios-44M1 2/58. "Cat's eye" is a rare non-serial lens with a unique aperture. Along with Zenitar-ME1 are very expensive.
Helios-44 is one of the most common Soviet lenses for SLR cameras. The number of only serial variations and modifications is amazing! There are more than two dozen of them! But besides the serial ones, there are very wild specimens, such as this Helios-44M1 2/58.

  1. Helios 44 58/2 lens series
  2. History. Lenses series "Helios"

It features an unusual two-blade diaphragm! Yes, yes, MS Zenitar-ME1 1.7 / 50 is not the only one of its kind, only in Helios-44M1 the hole formed by the diaphragm has the shape of a rhombus, not a square! This type of diaphragm is commonly referred to as "Cat's Eye". It is curious that on the first batch of MS Zenitar-ME1 1.7 / 50, the Cat's Eye diaphragm was also installed, only it was supplemented by two more petals, as a result the hole formed had the shape of an almost regular hexagon we are used to. Later on Zenitar still left two diaphragm blades, forming a hole in the form of a square.
For an inexperienced amateur photographer, a diaphragm of this shape may seem like a kind of perversion. However, the proposed design of the cat-eye iris diaphragm has been known in the optics literature for a long time. It was used mainly in scale cameras and inexpensive video cameras, the optics of which did not differ in high resolution. However, in high quality photographic systems, the use of a diamond-shaped aperture is unacceptable due to strong optical distortion.

But since Helios-44, however, like Zenitar, is not a high-resolution lens, in 1979 it was decided to release an experimental batch of lenses Helios-44M 2/58 and Zenitar-M 1.7 / 50 with a cat's eye aperture. During the testing of prototypes, it was found that the transition from a round pupil to a diamond-shaped one had little effect on resolution. But at the same time, the contrast of the image worsened, which was also revealed when measuring the frequency-contrast characteristics.

The second disadvantage of using a diaphragm of this type was the violation of the uniformity of the distribution of illumination over the image field in different directions. This feature leads to distortion of the color rendition across the field of the picture when photographing on color film.
The unusual shape of the diaphragm, which is not used in high-aperture photographic lenses, creates an aesthetically unacceptable pattern in the out-of-focus area. For this reason, and also because of the fear of a large number of complaints about cameras with such a lens, the KMZ management decided to release a trial batch of experimental Helios-44 to begin with. These optics were supposed to be handed over to qualified consumers, to amateur photography clubs, etc., and based on the results of their operation and feedback, a decision was made on the possibility of producing lenses with a similar aperture on the domestic market. As you know, the serial production of lenses with the "Cat's Eye" diaphragm was not destined to come true.

Gelios 44M1 2
Photos of a unique copy of the lens with a diamond-shaped aperture - Helios-44M1 2/58 could be found on the website Flickr.com, they were posted by a user under the nickname Convert1. There were also two test photos, which can be used to judge the bokeh of the unusual Helios. What can we say - the blur in the zone of blur, like that of the MS Zenitar-ME1, is very specific.

Gelios 44M1 4

Use on modern cameras

On a camera with APS-C sensor (kf = 1.6) the camera will have a field of view equal to the equivalent 93mm focal length, and the aperture will correspond to the value f / 3,5... Why is that? Because, firstly, because of the narrow viewing angle, you will have to move further. Secondly, the camera's sensor receives 1,6 times less light than a full-frame 35mm sensor. Thirdly, although this does not apply to the previous two statements, the lens on the crop has a drop in sharpness due to the denser arrangement of pixels on the matrix and their concentration in the center of the lens.

On a full frame, the lens works as intended - it has a more flexible picture and characteristics corresponding to the declared ones.

The easiest way to shoot is in the mode Aperture Priority (Av), when the camera adjusts the required shutter speed based on the current aperture value and the light in the frame. To work on digital cameras, you will need an adapter from the M42x1 threaded connection to your camera. Helios-44M1 2/58 it is easiest to put on Canon EOS with EF (-s) mount, due to the insignificant difference in focal lengths. Adapters without focus confirmation chips are cheap.

  • The material from the site was taken as the basis for writing the article. www.zenitcamera.com
  • Photos taken from the site Flickr.com from album of user Convert1:
  • Article found here

Adapters for cameras and lenses

Sometimes I buy photographic equipment from the USSR and not only. You can offer your write me. Help the project: 5469 1200 1062 4624. Comments can be left without registration and SMS

Add a comment

Your email address will not be published.