Material according to PUSK-16 specially for Radozhiva prepared Rodion Eshmakov (subscribe to Instagram!)
PUSK-16 (50 / 2.8)
Among technical optics, there are many unusual and interesting solutions that cannot be found among ordinary photographic lenses. Not always, such optics can be more or less successfully / simply applied in photography, which limits the interest of amateur photographers to such "toys".
The lens after adaptation has nothing in common externally with the previous appearance.
At the time of this writing, the hero of this review still hasn't come out of the shadows: the lens of a very rare technical camera PUSK-16 rarely comes across in the secondary market, and hardly anyone has ever seen the camera. Someone positions him as an "honest makrushnik" (s), someone truthfully says that he does not know for what and from what he is, and how he can be used. This article presents a PUSK-16 camera lens adapted for use with modern SLR cameras.
Specifications:
Optical design - 6 elements in 5 groups (analogue of P-Flektogon);
The optical scheme was not found in the sources. This drawing was made by me based on the results of inspection and disassembly of the lens.
Focal length - 50 mm (exact - unknown);
Relative aperture - F / 2.8;
Aperture - 10 blades, pre-lens;
Frame format - 6.2 * 10 mm (16 mm film);
Features: technical lens. Not suitable for use without invasive adaptation.
Design and adaptation features
In the factory version, the lens is a cylinder that is too long for a fifty-kopeck piece with a helicoid (with a focusing range from infinity) and a diaphragm, but with an extremely inconvenient attachment to the camera. The appearance is quite typical for Soviet reproductive optics (similar, for example, RP-457).
However, the owner of the lens will not be able to see the pre-lens diaphragm just like that: it is hidden behind the 7th element of the optical scheme - the front plane-parallel coated glass. Just like in Tair-62T there was a field diaphragm in the tail of the lens unit, covered by a glass plate, this lens has a field diaphragm in the front of the lens unit. In other words, it can be assumed that the angle of view of the lens is artificially reduced for use with a narrow film camera.
Factory photographs taken from a famous auction in the CIS.
The optical design of the lens is highly asymmetric: it looks like a retrofocus double Gauss with a reduced front half and a massive rear lens group. This very atypical solution in optics is used to create lenses with a large back focal section and a raised entrance pupil - thus, it is possible to level vignetting when shooting through narrow apertures. The objective lenses have a green tint (perhaps this is an early Soviet multilayer coating), which does not significantly affect the color rendition of the lens.
A very similar optical design - P-Flektogon - was used in the lens Carl Zeiss Jena SO-3.1which was developed in the 1970s for the Stasi (secret police of the GDR) and was used for tracking through small holes.
Optical design of the P-Flektogon 35 / 2.8 objective.
The German lens is designed for a 36 * 24 mm frame, i.e. is wide angle. One of its features is a strong (5%) barrel distortion, which is extremely difficult to correct with such asymmetry of the circuit.
The scheme of the Soviet lens is noticeably simpler, so there is no reason to hope for a 60 ° field of view and high optical characteristics, but we can definitely assume that the PUSK-16 lens will cover a frame of a sane size.
To increase the working field of the lens, a radical alteration of the body was necessary: the lens had to be completely disassembled and cut down absolutely everything, leaving only the tube with the lenses. The manufacturing quality of the lens unit, it should be noted, is low - very poor or absent blackening, the lenses are enclosed in aluminum pancakes.
In this case, the lens loses the helicoid and the diaphragm mechanism. I installed it in the Helios-44m body, and took the diaphragm from the Korean 135 / 2.8 misunderstanding and, as in the original lens, installed it in front of the front lens.
Unusual pre-lens aperture of the adapted lens.
Since in the 1970s the Koreans mastered the production of good "blinking" apertures, but not optics, the lens aperture setting mechanism is rather unusual: the ring must first be set to the desired value, guided by the risks applied at intervals of one stop, and then the aperture must be closed to the selected value. lever. Yes - if you put a filter on the lens, you won't be able to use the aperture.
The Helios-44m shank had to be slightly bored in order to bring the massive rear lens group closer to the matrix and make the lens available for use on SLR cameras (including full-frame ones). Adaptation to Nikon cameras is theoretically possible.
View of the tail section of the adapted lens.
The gutted Helios-44m has a convenient helicoid with a long stroke, which provides a short minimum focusing distance.
Lens when focusing at close distances.
Thus, the unusual design of the PUSK-16 camera lens makes it possible to use the lens even on a full-frame SLR camera, but this requires a technically not complicated, but laborious adaptation. The optical design of the lens hardly bodes well for high image quality, but it can definitely "distinguish itself" with something.
Optical properties
In short, this is probably the most unsharp 50 / 2.8 lens that I have come across. But it is also the most expressive 50 / 2.8 lens. The generated image has an acceptable resolution only in the central area of the frame, is characterized by a strong barrel distortion for a “fifty kopeck piece”, very large vignetting in the full frame (black corners, especially at strong aperture). With aperture, even up to F / 11, the situation in the frame field of 36 * 24 does not fundamentally change - sharpness is achieved only within the APS-C / MFT frame.
It would seem that it is impossible to shoot with this miracle. In reality, everything is not so bad: at medium focusing distances, vignetting is subtle, sharpness at F / 2.8-F / 4 is enough for a central composition, distortion in many scenes does not matter.
Moreover, the lens has a very, very unusual, bright bokeh: the discs of confusion have a bright edging; at the edges of the frame turn into ellipses with uneven brightness distribution - a consequence of pronounced field aberrations. Thanks to the unusual blurring of the background, photographs taken in nature when focusing at close distances look spectacular. However, an interesting result can be obtained with it even in portrait photography.
Below are sample photos taken with the Sony A7s full-frame camera.
Conclusions
The PUSK-16 camera lens was most likely never designed for use with full-frame DSLRs. Who, however, knew that in a frame of fourteen times the area from a native, this nondescript lens with optical quality at 2+ would prove that 50 / 2.8 "bockenators" also exist?
You will find more reviews from readers of Radozhiva here... All Rodion reviews in one place here.
I still did not understand why it was necessary to expand the image field? He would have done much better at his 16mm
Do they use a lot of them on Nikon J and BMPCC, or is it some kind of subtle trolling?
No, it's just that this rework is a different lens rather than the original. Something like a peephole from the zenith)
Never. The optical part is unchanged. The fact that I removed the “hood” does not mean that this is a different lens. Or, in your opinion, if you take a half lens with a 32 * hood, will it be a different lens?
Rodion
It is more interesting to test the novelties of KMZ / SHVABE for 54-56 thousand rubles, which have just gone on sale in the KMZ online store.
Is it worth it?
Well, write to them and test) And even better - support the domestic manufacturer and buy)) Desirable all 4 new items ...
And what are you immediately threatening?
Where is the threat? It is at least strange to point out what is “more interesting”, but it costs 56 tr. Especially considering that, as you know, KMZ does not want to give lenses for review - both I and Arkady have already written to them.
You offer a person to give the national currency in blood for a national analogue. It's cruel!
KMZ is not Cosina / Voigtlander or Zeiss, but prices are already close. $ 740 for a manual 50 / 1.5? I'm sure they don't have a goal to attract a mass buyer. Most likely orientation towards the Western market.
Prices are tin. For whom they are designed - FIG knows. I do not think that in the Russian Federation or nearby satellite states there are many who want to purchase them at such price tags. Perhaps the famous photographers Dmitry Medvedev and Lenya "Cosmos" (Chernovetsky).
By the way, wouldn't it be a reason for hucksters from different trading floors to raise the price tags for old Helios, Jupiters, OKSs, etc.
As for Rodion's creation, for flowers and the like, the lens creates a good salary, but for portraits, the background must be unambiguously chosen. From blurry twigs ripples and strains.
However, Rodion, thank you for your creativity and finding such "rarities" and their adaptation.
The hucksters, on the contrary, cannot sell their OKSs, because there is China.
Basically, if you deliberately remove all objects from the focal plane so that everything remains blurry, you will get a wonderful psychedelic.
In the picture, in places it resembles some creations of the Lensbaby company
Anyway, it's not sharp. For such a bokeh, he can be forgiven for everything. A very interesting picture. Thanks for your review!
This is usually the case - either bokeh or sharpness. Another thing is that sometimes there is neither one nor the other.
Hi, where is the front lens group?
I mean where? The lens, according to the calculation, has an aperture in front, this is how it was invented from the factory. All lenses are in place.