Review of the lens MC PENTACON PRAKTICAR 1: 2.4 f = 50mm specially for Radozhiva prepared Rodion Eshmakov.
Perhaps, every keen amateur photographer has once heard about German “staff” - tesars and biotars. However, this lens is neither one nor the other, and for some reason it has undeservedly remained in the shadow of famous ancestors.
Prakticar 50 / 2.4 is a compact full-time lens for the updated Praktica B series of cameras in 1979. The lens occupies an intermediate position between the old Zeiss Tessar 50 / 2.8 and Pancolar 50 / 1.8 and was created as a rethinking of the Tessar 50 / 2.8 - “whale” lens (in The USSR served as a similar lens Industar-50 50 / 3.5). This review presents a lens redesigned for use with Canon EOS cameras.
Optical design - 4 lenses in 4 groups, Ernostar, view of the design in the review text below
Focal length - 50 mm;
Relative hole - F / 2.4;
The diaphragm is six-petal, F / 2.8-F / 22, with clicks on the half-stops, “jumping” (the alteration did not preserve this mechanism);
The minimum focusing distance is 0.6 m;
Thread for filters - 49 mm;
Features - Praktica B mount is incompatible in r / o (44.3 mm) with modern central control valves.
Historical background - source [http://zeissikonveb.de/start/objektive/normalobjektive/prakticar%202,4.html].
History of development
Designed back in the 1930s, Carl Zeiss Tessar has firmly taken the niche of standard 35mm camera lenses. At an angle of about 50 °, its distortions were corrected very well up to F / 4, but with the aperture increasing to F / 2.8, the image quality formed by the lens on an open aperture fell sharply. Further development of the optical scheme implied either the use of expensive grades of glass, or the use of aspherical lenses. The second was implemented in 1935 in Germany - the experimental aspherical Carl Zeiss Tessar 50/2 was obtained, but this idea was not developed.
An advanced version of the standard lens at that time was Carl Zeiss Biotar 58/2, which, moreover, was much more expensive than Tessar: more lenses, glued surfaces and greater accuracy of the equipment were required.
Attempts to add a link between Tessar and Biotar were made in 1956: after successfully calculating the medium format Biometar 80 / 2.8, Zollner also calculated a small format analog that showed better resolution than Tessar 50 / 2.8 on laboratory photographic materials. Unfortunately, the quality of mass film at that time left much to be desired, and Zeiss did not introduce this relatively complex five-lens lens into production. Tessar remained the only one in his class in the Carl Zeiss Jena line until 1987.
The development of a cheap and light full-time lens for SLR cameras was an especially attractive task - since it allowed to make an image in JVI brighter and easier to focus on. So, Ubert Ulbrich, Wolfgang Hacking and Wolfgang Gröter worked at Meyer-Optik Görlitz to create a standard 50 mm lens with aperture 1: 2.4, the cost of which would not differ much from 50 / 2.8 optics. Splitting the front component of the well-known Triplet into 2 lenses, they added the parameters necessary to improve the correction. The most important technique turned out to be the use of a thick meniscus with a low refractive index and precisely selected dispersion as the second lens. In addition, all lenses used high-refracting glass with a coefficient above 1.6: heavy crowns SK24, SK6, SSK5, heavy flint SF17. The result was registered in the GDR (patent 70.182 from 23.08.1968).
Alas, such an interesting lens turned out to be for decades: the niche of the regular Carl Zeiss Jena camera lenses was firmly occupied by Tessar, released in large quantities. The situation changed only with the release of Praktica B200, which appeared in the late 80s. At first, the camera was packaged with the MC Prakticar 50 / 2.8, a converted 1947 Tessar with multilayer enlightenment, but its price did not match the quality. And it was a great chance for the development of Meyer-Optik. The new lens, called the Prakticar 50 / 2.4, had a modern compact design and good optical quality at a low cost. Interestingly, Prakticar 50 / 2.4 was available for a considerable time after the reunification of Germany.
It is worthwhile to dwell a little more on the optical scheme of the lens: it is not difficult to notice a certain external similarity between the famous Meyer Primoplan 58 / 1.9 and the modest Prakticar 50 / 2.4. Thus, optically Prakticar 50 / 2.4 is closer to rare among staff members Ernostar Berthele than to Tessar Rudolph. Only Japanese Fujinon 55 / 2.2 and 55 / 1.6 can be cited as close lenses.
For use with modern CZKs, the lens requires reworking - the working length of the PB mount is too small to allow the use of adapters. For Canon cameras, simply replacing the lens mount with a M42-EOS flange, sharpened to the desired thickness. Alteration for Pentax cameras affects the helicoid of the lens, but allows you to save even automatic iris control [details]. Alterations for Nikon cameras will be significantly more difficult.
Prakticar 50 / 2.4 is made in accordance with the style of the German optics line of the 1980s: corrugated aluminum rings are coated with pleasant to the touch black paint, on top of which (alas, without engraving) are applied the depth of field, aperture and distance scales. The distance is marked both in meters (white numbers) and in feet (green numbers). The red dot on the IPIG scale indicates the IR shift mark. By the way, there was a more expensive version of the lens, which was even more compact and had a rubberized focus ring.
A rather thin focusing ring has a stroke of almost 360 °, but the lens block travel is small and the MDF is 0.6 m. This is probably better than 0.75 m for Primoplan 58 / 1.9, but it is much worse than 0.3 m for Industar-61 LZ MS , eg. In the process of focusing, the lens block moves only progressively, while the trunk with a thread for filters (49 mm) leaves.
Prakticar 50 / 2.4 lenses have a bright red-orange tint, while the light transmission has no noticeable distortion.
The diaphragm of the lens has only six blackened petals, which form when the saws are gradually closed first, and then the usual “nuts”. The diaphragm ring has clicks on the half-stops.
It seemed to me that the Prakticar 50 / 2.4 looks pretty nice and easy to use (although the focus ring is narrow). A big plus is its small size. A significant drawback is the lack of engraving of the scales on the case - marks on top of the black coating tend to quickly wear out from mechanical influences.
The Prakticar 50 / 2.4 image on the open aperture is sharp enough in the center of the frame (resolution is limited by spherical aberration), but the edges are influenced by field aberrations (mainly coma and astigmatism). Vignetting is noticeable only at full frame. The lens has good resolution in the center of the frame with ~ F / 3.5, and in the field it is achieved with ~ F / 5.6-F / 8 for APS-C and with F / 8-F / 11 for full frame. The contrast of Prakticar 50 / 2.4 is good due to multilayer enlightenment, color reproduction without noticeable distortion.
A pleasant difference from tessars and triplets is a soft pleasant bokeh: circles of blur have an unexpressed light border, and at the edges of the frame they turn into ovals.
In my opinion, optically Prakticar 50 / 2.4 is significantly ahead of its predecessor both in image quality and artistic properties.
Below are examples of photos on the Pentacon Prakticar 50 / 2.4 and Sony A7s (RAW development in Imaging Edge, part of the photo in the “Standard” preset, and part - “Autumn leaves”).
An unpopular mount and a modest name apparently hid this wonderful lens from many amateur photographers. Meanwhile, Prakticar 50 / 2.4 is a good and balanced fifty dollars with a nice pattern, rare optical design and low price in the secondary market.
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