Let’s have a look at 44m-5, 6-44m, 44m-7 lenses. You can see that their names are written in Latin, and quite seldom in Cyrillic.
Such lens versions as MS Helios-44m-X contain X-7, 6, 5, 4 in their names and they have a sign «Zenit» located around the lens name. Also this model has the symbol of the optic-mechanical plant in the town of Valdai in Russia. Names like «MS HELIOS 44M-4 2/58″ (Valdai) also occur, but they do not contain the name of Zenit and a special bar located between the number and the name. The name is similar to «MS Helios 44M-4 2/58″ (plant in Krasnogorsk).
When we talk about lens modifications, we should name the main 2/58 type, which includes Helios 44-7 version, and it doesn’t have “MS” in its name. This model was intended primarily for the camera «Zenit-7″. Similarities with 44m-7 versions are likely to be excluded.
If you return to MS Helios-44M-7 2/58 lens, you can draw the conclusions about its optical features. Among all 2/58 Helios lenses this model can be called the sharpest. This is possible due to the fact that the resolution power of this model are remarkable compared to other models. Its resolution is 50 lines per millimeter in the center, and 30 lines per millimeter at the edges of the shot. There is no need to recommend MS Helios-44m-7 taking into consideration its high cost compared to almost the same models. Due to the time of their production Soviet lenses can lose their former condition, but at the same time the field performance of MS Helios-44m 6 58mm F2.0 model is higher than the model named above.
Helios F2.0 58mm models were created in terms of the basic optical system Carl Zeiss Jena Biotar 2/58. HELIOS-44M-7 2/58 is the flagship member of the Helios-44m-X family. The most suitable lenses to choose are the first Helios-44 models of a white body having a 13-leaf aperture with a convenient control ring.