Zenith TTL

For the Soviet camera industry, Zenit-TTL was a progressive model that brought together many new products in one building. The most important of these was the TTL exposure meter , which had previously been used in the smaller Soviet cameras Zenit-16 and Kiev-15 ^[4] . In addition, the camera was the first of the Zeniths to receive a rewind tape and a non-rotating shutter speed, which allowed semi-automatic exposure control due to interfacing with a variable resistor ^[5] . In previous models, the shutter speed was rotated when the shutter was released ^{[* 1]} . Another innovation was the lock of the back cover, which opens when pulling the rewind tape, and not a separate leash. The multi-slot receiving coil of a new design simplified the charging of film ^[1] .

At the same time, Zenit-TTL is a vivid example of the “cosmetic” modernization characteristic of the Soviet camera industry of the stagnation era . The design used outdated technical solutions, inherited from the very first Zeniths , and limiting functionality. This applies to the field of view of the viewfinder, displaying only 65% ​​of the area of ​​the future frame, and the shutter with a horizontal stroke of cloth curtains. If the absence of a “moderator” and shutter speeds longer than 1/30 of a second are not important for an amateur-class camera, then the shortest shutter speed of 1/500 in those years was characteristic of the most primitive cameras with a central shutter . Exposure to synchronization in 1/30 of a second made it almost impossible to use a “filling” flash in sunny weather.

Another weak point of the camera was the obsolete mechanism of the pressure diaphragm driven by the shutter button. Because of this, the effort on the button was significantly higher than in the earlier Zenith-E model, reducing stability at the time of shooting. In all these parameters, Zenit-TTL was even inferior to the equipment of the Eastern block , for example, Praktica cameras, which were already equipped with modern lamella shutters and an independent jumping diaphragm drive. The 1969 Praktica LLC model measured exposure through the lens with the aperture open, while the Zenith-TTL only measured its working value ^[6] . Most amateur cameras abroad were already equipped with automatic exposure control , and Kiev-15, released four years earlier in the USSR itself, worked in shutter priority mode . The screw mount of the lenses by the time the camera was released went out of use with most camera manufacturers, giving way to a more progressive mount . Frame counters of foreign cameras were automatically reset to "zero", which was not in the "Zenith-TTL".

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  Zenith TTL with Olympic symbols

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  Battery Socket

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  Leather case

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  Light selection circuit

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  Photoresistor Location

Along with these drawbacks, which were also characteristic of previous models, the early Zenith-TTL releases had a too dark viewfinder , making focusing difficult. The image in the eyepiece was significantly darker than in older models without a TTL exposure meter. The reason was the method of selecting light for which a translucent front face of the pentaprism was used . She reflected into the eyepiece only part of the light from the lens, and the rest of the luminous flux passed to the cadmium sulfide ( CdS ) photoresistor . In later modifications developed in 1982, it was possible to get rid of this drawback by placing a pair of photoresistors behind the ocular face of the pentaprism. This design has been used in most foreign cameras since 1967, when Asahi Optical's patent was obtained for it ^[7] . A camera with this arrangement of photoresistors since 1983 was produced under the name Zenit-12 , but the same changes were made to the design of the base model ^[8] . A year earlier, the “ cold shoe ” was replaced by a “ hot shoe ” with an additional contact of the cordless flash synchronization ^[9] .

In general, the Zenith-TTL was inferior to the predecessor of the Zenith-E, which had an informative viewfinder and a soft descent. Photographers who shot black and white negative film often preferred an older model because they measured exposure with an external light meter or determined it empirically. Nevertheless, in the complete absence of competition with foreign equipment, Zenit-TTL was popular in the USSR domestic market , and was even “fashionable”. The TTL exposure meter was used for the first time in a camera produced in such a massive print run and turned out to be much more accurate than selenium exposure meters of previous models with an external photocell. This circumstance was decisive when shooting on a color reversible film, which at that time had gained popularity in the USSR. In addition, Soviet counterparts such as Kiev-15, despite the superiority in basic parameters, were inferior to the availability of interchangeable optics with a unique bayonet mount, and were produced in very small quantities. Zenit-TTL could work with a huge fleet of threaded lenses already released in the Soviet Union at this point. Released two years later, Zenit-19 had a more modern design, but its release was very limited.

The retail price of the Zenith-TTL in 1980 with the Helios-44M lens was 240 rubles , and in 1983 it was reduced to 210 rubles. In the western market, Zenit-TTL proved to be competitive due to its very low cost compared to peers. The sturdy cast case and glass lenses in a metal frame for amateur photographers looked more solid than the cheap Japanese "mirrors" with lots of plastic. Large batches of cameras were exported, including under the name Cambron-TTL, assigned to it by the Cambridge Camera Exchange network in the USA ^[10] . A significant share was the UK market, where aggressive marketing was conducted and there was a developed TOE warranty service network ( Eng. Technical & Optical Equipment Ltd ) ^[11] . In the British market, the camera turned out to be the cheapest equipped with a TTL-exposure meter, selling for only 75 pounds ^[12] . In the Neckermann Herbst / Winter 1981/82 catalog ( Germany ), the price of a Zenit-TTL camera with a Helios-44M lens was 229 brands in Germany , while the cheapest EM model from Nikon SLR cameras cost 499 brands.

• The regular lens is Helios-44M 2/58.
• The type of photographic material used is perforated film film 35 mm wide ( film type 135 ) in cassettes. Frame size - 24 × 36 mm.
• Shutter type - mechanical, curtain-slotted with horizontal movement of cloth curtains. Shutter speeds are from 1/30 to 1/500 s (automatic), “ B ” (by hand) and long. Shutter speed with electronic flash - 1/30 s.
• Lens mount type - M42 × 1 threaded connection . The working segment is 45.5 mm.
• The type of focusing screen is a Fresnel lens with a matte ring and a microraster .
• The magnification of the eyepiece is 5 ^× .
• TTL-exposure meter (objective lens exposure metering) with cadmium sulfide ( CdS ) photoresistor FPF-9-2 located on one of the faces of the pentaprism with a translucent mirror coating ^[5] . In later models (released after 1982) - two photoresistors located on the back of the pentaprism, which allowed to increase the brightness of the viewfinder. The dial indicator of the exposure meter is visible in the viewfinder . Semi-automatic exposure setting on the aperture closed to the working value. When the film photosensitivity is set and the shutter speed is set by rotating the aperture ring, the dial indicator should be set to neutral. The range of photosensitivity of the film is 16-500 units. GOST. When applying filters, corrections are automatically made for their density. In the exposure device , a measuring bridge circuit is used ^[5] .
• Sync contact “ PC ”, central sync contact only on cameras of the 1980s .
• The case is cast from an aluminum alloy, with a folding back wall.
• Trigger cocking shutter and film rewind. Rewind tape.
• Repeater aperture and the inclusion of exposure meters - from the shutter button.
• The power source for semi-automatic exposure metering is a D-0.06 disk nickel-cadmium battery ^{[* 2]} or an RC-53 ^{[* 3]} mercury-zinc cell (a modern analogue of PX-625 ^{[* 4]} ).
• Tripod socket thread - 1/4 "
• Mechanical self - timer .

Zenit-TTL has become the base model for a number of KMZ cameras, unofficially referred to as the 12th Family.

• Zenit-12 is similar to the Zenith-TTL configuration since 1983 , with an improved level of manufacture of a number of units and a better finish. Serially produced from 1983 to 1994 . Delivered on special orders and for export .
• " Zenit-12sd " - ("sd" - LED ). The main difference from the Zenith-TTL is the replacement of the dial indicator of the exposure meter with two LEDs . Depending on the mode of combustion of the LEDs , “underexposure” or “overexposure” or the correct exposure is determined. Power source - two SC-32 elements (analogue - SR44). Brighter viewfinder (changed the location of photoresistors ). Hidden rear wall lock, modified shutter button and film rewind button, tripod socket in the center of the camera.
• Zenit-12xp is an export version of Zenit-12sd. The sd index was in tune with the abbreviation of the Nazi organization , therefore the name was changed to XP .
• Zenit-15, including without TTL - exposure metering device ( BelOMO ).
• Zenit-15M ( BelOMO ).
• " Zenit-21XS " - a modification of the "Zenith-12xp" ( BelOMO ).

In the 90s , the production of the following models began:

• Zenit-122 - modernization of the Zenit-12sd camera (Zenit-12xp) - a redesigned indicator of the exposure meter with three LEDs, the replacement of a number of metal parts with plastic . BelOMO produced Zenit-122 without a TTL light meter .
• "Zenit-122V" - a camera without a self-timer ( KMZ ).
• "Zenit-122K" - with a bayonet mount K ( KMZ ).
• " Zenit-130 " - a modification of the "Zenith-122" ( BelOMO ).
• " Zenit-212k " - with a K mount , a modified design , an increased shutter speed range ( KMZ ).
• “ Zenit-312m ” - “Zenith-122” with a modified design ( KMZ ).
• " Zenit-412DX " - a modification of the "Zenith-122", the introduction of photosensitivity according to the DX-code ( KMZ ).
• Zenit-412LS is the latest production model of the line. Modernization of the Zenit-412DX camera, in terms of expanding the range of the photosensitivity of the film perceived by the exposure meter according to the DX code .

• Kiev-19

• A. Akalupin, G. Sysa, S. Lerman. The new Zenit-TTL camera (Russian) // Soviet Photo : magazine. - 1977. - No. 8 . - S. 42, 43 . - ISSN 0371-4284 .

• N. Marenkov. The Zenit TTL camera (rus.) // Science and Life : Journal. - 1981. - No. 3 . - S. 94-96 . - ISSN 0028-1263 .

• Yu. Ryshkov. A Brief History of the Soviet Camera (1929-1991) / B. Bykov. - R .: PTK "Art", 1993. - S. 32–41. - 72 p. - 5,000 copies. - ISBN 5-88330-002-2 .

• V. Feday. From “Moscow” to “Zenith-Up” (Russian) // “ Photography ”: magazine. - 1992. - No. 1 . - S. 42-44 . - ISSN 0371-4284 .

• Malcolm R. Hill, Richard McKay. Soviet Product Quality = Soviet Product Quality / RW Davies. - 1st. - London: Macmillan Press, 1988 .-- ISBN 978-1-349-09292-5 . - DOI : 10.1007 / 978-1-349-09290-1 .

• Stages of development of the Soviet camera industry. Zenit-TTL, Zenit-12, Zenit-15
• "Zenith-TTL", instruction manual.
• Zenit-TTL instruction in pdf format.
• Line Zenit-12