Overview Helios-65T 1: 2 F = 5cm specifically for Radozhiva prepared Rodion Eshmakov.
Helios-65T 1: 2 F = 5cm
Helios-65T (KMZ) is a rare technical lens that has been used in television for projecting images (24x32 mm) onto the photocathode transmitting television tube. The most famous modification of this lens is Helios-65 Avtomat (Arsenal plant, Kiev) for Kiev-10/15 cameras, although it has already become rare.
Specifications ("Catalog. Lenses" Yakovlev, t.1, p. 96-98, 1971):
Optical design - 6 lenses in 4 groups (helios / biotar), with an enlarged rear segment, рисунок;
Focal length - 52.54 mm;
Relative aperture - 1: 2;
Aperture - 13 blades, manual control;
The back segment is 39.25 mm.
Features of the design and adaptation of the lens
The lens that fell into my hands was a lens block with a diaphragm and a mounting thread cut into most of the surface area of the lens. If you believe the only surviving photograph of the lens, then he had a focusing mechanism mounted on a massive base.
Photo Helios-65T in the original factory version. Taken here.
The lens was installed by me in the case of Helios-44M-7 with preservation of focusing at infinity and the possibility of manual control of the diaphragm. True, it is not the donor ring of the case that is used to adjust the aperture, but the nose of the lens (made, by the way, from the insert-hood of Industar-29) - longer in comparison with Helios-44.
Helios-44P (left) and adapted Helios-65T.
Despite the really large rear focal length (compare the ratio of the rear segment to the focal length for Helios-44 and Helios-65!), The lens is difficult to use on full-frame CZKs: the lens block has a rear lens recessed about 5 mm deep and the lens catches the mirror even at Zenith when focusing on infinity.
View of the adapted lens in the body of the G-44M-7. A noticeably strong protrusion of the lens block over the plane of the adapter M42-EOS.
The lens block is of good quality: the inner surfaces and ends of the lenses are blackened. Unlike the version for Kiev-10/15, this lens has a chic matte blackened thirteen-petal diaphragm, very similar to that used in the early Helios-44.
View of the Helios-65T diaphragm.
The optics of this Helios-65 modification carries a pink-violet enlightenment, typical of early Helios-44 modifications, which allows one to estimate (the number on the lens is not “speaking”) the time of its release as the end of the 50s and beginning of the 60s of the last century. Such enlightenment distorts the transmission spectrum of the lens: the reflection of blue-violet rays warms the picture. This is especially noticeable in comparison with my Helios-44P with lenses of the late MS version.
When looking at the clearance through Helios-65T, color distortion is noticeable, in contrast to the modernized Helios-44.
Structurally, the Helios-65T in the redone version turned out to be similar in parameters to the old Helios-44. Particularly enjoyable is the presence of an excellent multi-leaf diaphragm, which is a rare case for fifty-fifty class 50/2.
Optical properties
Helios-65T forms a picture on an open aperture with medium sharpness (slightly lower than that of my Helios-44) in the center and very bad (but hardly worse than that of Helios-44) - at the edge of the frame (even on APS-C) ... The subsidence of the resolution is a sacrifice made by the designers for the huge (for a fifty-kopeck piece of this type) rear section. In general, resolution is limited to spherical aberrations (in the center of the frame) and coma (at the edge). The lens has strong vignetting - more than 50% for a full frame (the light drops by half to the edge of the frame). Aperture up to f / 8 makes the sharpest across the entire APS-C frame; this is probably not enough for a full frame. Optical flaws, meanwhile, are a merit when it comes to bokeh. Helios-65T can claim the title of the champion in background twist among fifty dollars! The optimal aperture from the point of view of the balance of artistic properties and resolution is f / 2.2-f / 2.5: unnecessary spherical aberrations disappear, and the picture remains recognizable.
Bokeh and lens sharpness at f / 2
Bokeh and lens sharpness at f / 2.2
Enlightenment distorts the color rendition of the lens, giving photos a warm shade. In the backlight, the lens does not feel well, despite the manufactured “hood”: the contrast decreases, the veil appears. In hard light, rainbow-violet highlights are visible.
Helios-65T 50/2 is very similar to the familiar Helios-44 58/2. Everyone can evaluate the degree of their differences and similarities from the following paired photographs taken in equal (as far as possible) conditions. All photos are taken on an open aperture, unless otherwise indicated. Photos take turns in pairs.
In my opinion, the Helios-65T has a more expressive bokeh than the Helios-44, although it loses to it in sharpness.
More examples of photos on Helios-65T are given below (Canon 600D, development from RAW to Canon DPP).
Conclusions
The rare Helios-65T 50/2 is a worthy, but hardly the best representative of its family. Optically, it’s pretty weak, but isn’t its strength in this weakness?
Thank you for your attention, Eshmakov Rodion.
You will find more reviews from readers of Radozhiva here.
Arkady, typo: "thirteen-petal"
Duzh garnі photo.
Greetings!
I really like the lens and the photos made by him! Wow!
We all need to throw in a7 for Rodion at least - how much longer can one be engaged in mental extrapolation of the behavior of lenses in a full frame? )))
This is a good idea, I have repeatedly offered him. Maybe he will listen not to me, but to others. Will we make him a donut?
Rodion, thank you, very high quality material. It will be easier to adapt with a7 soon
Dyakuyu, even tsikavo, know only at Radozhiv. Rodion is beautiful :)