Pentaprism, Contax, Pentax and Pentacon

Who created the first 35mm camera, or the first 35mm single lens reflex camera?

Difficult questions. First, you would have to agree on what constitutes exactly a “real” 35mm camera, or a “real” 35mm SLR, and then, you would have to determine what really counts: is it presenting a prototype at a trade show, applying for a patent, launching a limited series production, or inundating the world with tens of thousands copies of a “game changing” camera?

It is generally recognized that with the Leica, Leitz created the first commercially successful 35mm camera in the early twenties, and but it was not until 1932 when they launched the Leica II that the rangefinder camera with interchangeable lens had found its “real” final form.

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Foca *** with a Foca turret viewfinder (left) / Olympus OM-1n (right) The Foca, a French derivative of the pre-war Leica, is a good example of what a rangefinder camera with interchangeable lenses looks like. With its pointy prism housing, the Olympus illustrates the typical SLR shape.

The Contax S

1932 is also the year when Zeiss launched Leica’s most serious pre-war competitor, the Contax.

Zeiss was at that time the largest manufacturer of cameras in the world. They had a long tradition of innovation and a great team of engineers; conscious of the limitations of the rangefinder formula, they kept on working on a better solution until, after the war, they finally presented the Contax S, one of (if not the first) modern 35mm single reflex lens camera.

With its pentaprism, its horizontal curtain shutter and its 42mm screw lens mount, the Contax S was very close to the typical 35mm SLR design, and should have been commercially successful.

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Contax S – (second series from 1950). Courtesy of Pentax-SLR.com – the best source of information about early SLRs (not only Pentax)

But at that time, the Zeiss factories were in the Russian occupation zone (soon to become the German Democratic Republic) and all sorts of issues slowed down the roll-out to production: the Contax S only started to be mass produced at the very end of 1949. The launch of the Contax S also coincided with the start the Cold War – products from communist countries were not always welcome on the more affluent markets of the West – and to make the matters worse, the East German entity of Zeiss lost the rights to the Contax name in 1956. After considering multiple options (including apparently the “Pentax” name), the East Germans rebranded their cameras “Pentacon” (a portmanteau for Pentaprism and Contax) and the Contax S line of SLRs was abandonned.

Why is a pentaprism so important, that Zeiss and (later) Asahi changed the name of their cameras to include “Penta”? 

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On the ground glass of a plate camera, the image is reverse (top/down, left right) – image courtesy of http://www.michaelstricklandimages.com/

Composing a picture on a piece of ground glass located behind the lens is nothing new (plate cameras have been following that model forever), but the image is reversed top-bottom and left-right, which makes the composing process very slow and totally unsuitable to candid photography.

If a mirror inclined at 45 degrees is placed behind the lens, and the image projected on a piece of ground glass, it is not reversed top/bottom anymore, but is still reversed left/right. The photographers has to shoot from waist level, after having used a magnifying glass for focusing. It’s workable, but not the best formula for action shots,  journalism or simply spontaneous family photographs.

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Nikon F3 with the pentaprism viewfinder removed: the image formed on the focusing screen is reversed laterally.

 

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Left is right, right is left and of course the Coke and Powerade labels are also reversed

The pentaprism addresses all those issues – and as we all know from experience  with SLRs, the image is fully redressed, focusing is easy, and eye-level composition makes action photography intuitive even for beginners.

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Nikon F3 – The view of the same scene from the eye-level pentaprism viewfinder

Asahi Optical Co

Asahi started manufacturing lenses in Japan in 1919, and launched the first Japanese 35mm single lens reflex camera – the Asahiflex – in 1952. It was inspired by the pre-war German Praktiflex, but brought some improvements:  it had two finders: a waist level through the lens viewfinder (for focusing)  and a smaller eye level optical viewfinder to be used when taking candid snapshots.

In two critical areas, the Asahiflex was not as advanced as the Contax S:  it did not have a pentaprism viewfinder, and it used a narrower 37mm screw mount.

Asahi’s first major innovation came two years later with the introduction of the instant return mirror on the Asahiflex IIb (1954). The IIb was without equivalent for a while, but the step forward it represented was nothing compared to Asahi’s next giant leap, with the “Pentax” of 1957. The first (mass produced) Japanese camera with a pentaprism, it combined for the first time in a compact, elegant and well made camera the instant return mirror, the film advance lever, easy film loading with a hinged back, and the 42mm screw mount.

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The original Asahi Pentax camera from 1957 (source: official Pentax Web site).

The Pentax line of cameras sold by the millions and became the model that all other manufacturers would copy in the subsequent years. The Pentax name became so well known that the Asahi Optical Co. decided to sell all its products (including its line of medical equipment) under the name Pentax, before it finally changed its own name to Pentax Corporation in 2002.

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Pentax Spotmatic F from 1973 (left) and Nikon FM from 1977 (right). More than 15 years after its launch, the design of the “original” Pentax was still the model that all camera manufacturers were following

It is widely assumed that  “Pentax” is also a portmanteau for Pentaprism and Contax. According to Wikipedia, the name was purchased  by Asahi from the East German Zeiss  company just before the launch of the original Pentax SLR in 1957.

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Asahi Pentax – the top plate of the original model (1957) – source: eBay
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The Pentax Spotmatic F on 1973 – still true to the model defined by the “original” Pentax of 1957

Today, the single lens reflex formula is on its last breath – superseded by mirrorless cameras where the pentaprism has been replaced with a high resolution LCD – the Contax brand is dormant, and Pentax, as a subsidiary of Ricoh, is in life support with a line of three rather old dSLRs and no plan to launch a mirrorless system.

Sic transit…


More about

By far the most comprehensive source about Pentax cameras, as well as early SLRs of all makes: Pentax-slr.com

Asahi Optical Historical Club 

The official corporate history of Pentax (the Ricoh-imaging-co Web site)

The Asahi Pentax original (AP) from 1957 – CameraQuest


From a Pentax to another Pentax…

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Big Birds – Mableton, GA – Pentax Spotmatic F. Lens Pentax Super-Takumar 55mm f/2
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Cumberland Island National Seashore (GA) –  Some of the islands of the national park are limited to 50 visitors/day and have to be vacated before sunset. Pentax *ist DS – Lens Pentax 18-55mm
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Cumberland Island National Seashore (GA) – The Cumberland forts were built by the British in 1733 to protect their most southern colonies from the Spaniards. The forts were abandoned after the final defeat of the Spaniards at the Battle of Bloody March in 1742. Pentax *ist DS. Lens Pentax 18-55mm

The Contax ST – first impressions

A compact point of shoot camera from the late eighties, the Contax T2, is currently red hot, selling for obscene amounts of money (well above $1,000). We’re observing here the manifestation of a new trend – a few film cameras have suddenly reached stardom – and make you pay dearly for them –  while the mass of the point and shoot and SLRs from the nineties still languish in the $5.00 bargain bin.

In the world of manual focus SLRs, Contax bodies and Contax Carl Zeiss lenses, while not exactly cheap, can still be had for a small fraction of the cost of this T2.

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Contax ST and Carl-Zeiss Vario-Sonnar zoom – 28-85 f/3.3-4.0

Zeiss and its sub brand Contax have a very long history – Carl Zeiss founded the company that bears his name in 1846 in Jena (Germany) and Zeiss launched their first Contax camera in 1932.

In the seventies, Zeiss signed a licensing agreement with Yashica (the Japanese company subsequently became part of the Kyocera group). Contax and Yashica never said much about the role split in their joint venture, and most of what we know is an educated guess. High level, the “Contax” branded cameras of the Yashica/Kyocera era were designed and manufactured in Japan with some input from Zeiss. The F.A. Porsche  studio (*) was in charge of the industrial design of some models. Yashica and Contax SLRs shared the same bayonet lens mount, and Contax cameras could be paired with Contax as well as cheaper Yashica branded lenses.

The “Contax Carl Zeiss” lenses were named after famous Zeiss lens designs (Distagon, Planar, Sonnar, ..) and benefited from Zeiss’ excellent multi-layer coating. Some of them were made in Germany, but the majority were manufactured in Yashica’s Japanese plants.

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Not as well considered as the 35-70 of the same series, the 28-85 is still an impressive piece of glass.

Because of their Zeiss and Porsche lineage, their beautiful industrial design and their advanced technical content, the Contax cameras of the Yashica era could be sold as premium products, for much more than what Yashica could have extracted from  their own line of SLRs.

In Contax’s product range, the top of the line was always occupied by a camera of the RTS family, and the bottom by derivatives and successors of their original entry level camera, the Contax 139Q (137 MA, 137 MD, 159MM, 167 MT). There was room in between for what we would now call a line of “prosumer” cameras.

Contax’s middle of the range cameras were a motley crew of SLRs addressing the needs of different niches – the S2 and S2b were semi-auto mechanical cameras, the RX had “a focus assist” system, the AX was an autofocus SLR designed for manual focus lenses (the lens had to be set to the infinite, and the film chamber was moving to adjust the focus).

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a very well equipped camera with a conventional user interface (continuous drioptric corrector, date back, illumination of the command dials, and locks everywhere)

Among them, my pick, the Contax ST,  was launched in 1992. It’s a somehow simplified and less bulky derivative of the RTS III, a full featured, motorized, manual focus camera with a large viewfinder, a bit like the Canon T90 from 1986. Its unique selling proposition was that the film pressure plate was made of ceramics rather than steel or aluminum (hint: the CERA in KYOCERA stands for Ceramics). I’m not sure that this ceramics pressure plate brought any real benefit to the photographer, but it spoke to the imagination.

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The four conventional exposure modes and the shutter speed dial on the left.

 

Of course, at the time the camera was launched, all major  manufacturers (Canon, Nikon, Pentax) had followed Minolta’s example and converted their whole SLR range to autofocus, so the manual focus ST is a bit of the odd man out.(**)

Very first impressions

It’s a beautiful,  very traditional SLR which exudes quality, with no autofocus, no modal interface, no menus, no control wheel, no matrix metering, no lithium battery, and a limited use of plastics.

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the exposure compensation dial, the metering selector and the electro-magnetic shutter release on the right. AEL (auto-exposure lock) is only available with spot metering.

The ST feels dense (heavy, but not too much) and falls very well in the hands. The commands are conventional, with an aperture ring on the lens, and a large shutter speed knob and an exposure compensation dial  on the top plate. Almost all controls (except for the shutter speed and exposure compensation knobs) are  secured by locks (like they are on a Nikon F4). There is only a tiny LCD (view counter and ISO display) at the right on the top plate.

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Sticking similarities – the importance given to the exposure compensation dial, selectors at the base of the big dials on the left and on right, and a common design language (on the right, Fujifilm X-T1)

For the anecdote, the body of today’s Fujifilm X-T3 looks very much like a small Contax ST, at the 2/3 scale, that is.  Even the location and logic of the commands is strikingly similar – with the emphasis given on exposure compensation over any other control –  you don’t need to search any longer where the designers of Fujifilm got their inspiration from.

The viewfinder is exceptional. Combining a high enlargement (0.8) and a long eye point (I don’t have the figure, but by comparison with other cameras, it’s really long), it offers a cinematic view of the scene. But at the same time, it’s old school – it’s graced with red LEDs, and the focusing screen does not seem to be one of those ultra fine and ultra luminous Acutemate or BriteMate laser etched screens – as a result the image is a bit darker than what you would see on a Nikon FE2, for instance (not by much, maybe 1/2 stop). The ST is also one of the few manual focus cameras with a continuously adjustable dioptric correction – all in all one of the best viewfinders of its time.

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A beautiful viewfinder – on the right the shutter speed, at the bottom-right the aperture, and the exposure counter on the left (it show 00 because the film is fully exposed)

Lesser Contax SLRs have a rubberized skin. that degrades over time – it’s not the case for the STs – they still look pristine 28 years  after leaving the assembly shop.

The lens mounts and lens mount adapters

Contax and Yashica had abandoned the 42mm screw mount in 1975 with the introduction of  the Contax/Yashica (C/Y) mount on the Yashica FX-1 and Contax RTS.

The original Contax Carl Zeiss lenses belong to the AE series. The design of the lenses was modified in 1985 to support the Program mode and the Shutter priority modes introduced on the 159MM – therefore the modified lenses are part of the MM series (for Multi-Mode). The two versions of the lenses are inter-compatible – you just don’t get the Program mode or the Shutter priority mode if you mount an AE lens on a body like the ST.

Other lens options

Contax Carl Zeiss Lenses in C/Y mount are rather expensive, even now. There are three alternatives if you don’t want to pay hundreds or even thousands of dollars for a lens:

  • Yashica lenses: Some models have a  very good  reputation (the prime lenses in the ML series, generally) – they were manufactured in the same plants as the Carl Zeiss series, but were not built to Zeiss specs and did not benefit from Zeiss lens treatment. People who have tested them next to Contax lenses say the color rendering and the micro contrast are different (which makes sense – each lens manufacturer has its “signature”).  Other series of Yashica lenses (DSB, YUS) are not necessarily that good –  do you research.
  • Third party lenses: very few independents offered lenses in the C/Y mount. Tamron and Vivitar had C/Y adapters for their respective universal mount systems. But does it really make sense to mount a Tamron or a Vivitar lens on a Contax camera?

Last but not least, you can also mount older 42mm screw mount lenses (from Yashica, Contax or other defenders of the Universal mount such as Pentax) thanks to an adapter proposed by Yashica. You can still find those adapter rings on eBay.

The elephant in the room – made in Japan or in Germany? 

There is no doubt where the bodies were manufactured – my ST proudly bears its “Kyocera-Japan” signature. The Contax Carl Zeiss zoom (the 28-85 f/3.3-4.0) that came with the camera was also made in Japan (no mention of Kyocera, though).

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No doubt – it’s a Kyocera (Yashica) camera and it was manufactured in Japan. (interestingly the lens shows absolutely no mention of Yashica or Kyocera)

In the early years of the Zeiss / Yashica collaboration, a lens could originate from the German workshops of Zeiss or from the Japanese factories of Yashica (even for a given model – some were produced simultaneously in Europe and in Asia). Over the years, the manufacturing activities were increasingly concentrated in Japan. I did not find any evidence that lenses made in Asia were better or worse than the lenses made in Europe – and I don’t think it matters:  they were all designed and manufactured to Zeiss’s specs with Zeiss’s T* multi-layer coating.

Buying Contax cameras and lenses today

In the nineties, Contax cameras were positioned and priced as premium products, a big notch under Leica, but in the same ballpark as Nikon’s or Canon’s Pro cameras.

Today,  their high-end bodies hold their value very well even if Leica R products remain more expensive.

The Contax magic percolates to Yashica ML lenses and to certain Yashica bodies (like the FX-3 Super 2000), which are also  sold at a premium, for products of a second tier brand, that is. The 21mm and 28mm wide-angle lenses are particularly sought for, selling for at least $350.00.

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On the right the Canon T90 from 1986 – like the Contax, a very elaborate manual focus camera. The User Interface is totally different, though.

The least expensive Contax SLRs are the entry level models (139, 137, 167) at less than $100.00 for a nice copy. Really sought after models like the RTS III, the S2 (the semi-auto camera) or the Aria (a compact SLR, the last camera in the Contax manual focus line and the only one with matrix metering) typically sell in a $350.00 to $600.00 bracket. The rest of the products (ST, RX, RTS I or RTS II) sell for approximately $150.00.

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They were competing on the shelves of the photo equipment stores in the early nineties – the Nikon N90x (right) represents state of the art (modal interface, matrix metering, autofocus, f/2.8 constant aperture zoom). The Contax ST, on the other hand, was spec’d like a pro-camera of the early to mid eighties.

But be cognizant that in order to enjoy the full Contax experience, you’ll need Contax Carl Zeiss lenses. It’s very difficult to find anything (even a very common Planar 50mm f/1.7) at less than $150.00, and really interesting lenses (the 21mm wide-angle for instance) can cost well over $1,000.

More about the Contax ST and the Vario-Sonnar 28-85mm f/3.3-4.0 in a few weeks, after a few rolls of film.  


The Contax brand has been dormant since 2005, and there is relatively little information about their products on the Web.

The best source is a site maintained by Cees de Groot: http://cdegroot.com/photo-contax/

Apart from that, you have Wikipedia (of course): http://camera-wiki.org/wiki/Contax/Yashica_lenses and a few sites compiling user reviews of SLR lenses.


(*) Porsche used to be a family business. And  everybody in that family seemed to be named “Ferdinand”. Because it was a family business, the eight grand-sons of Ferdinand Porsche, (the engineer who had founded the company and designed the original Beetle) ended up working at the Porsche car company under the direction of Ferdinand “Ferry” Porsche, who had taken over the business from his father Ferdinand after WW2. When the conflicts between the most talented of the cousins reached dangerous levels, Ferry asked them to leave. Ferdinand Piech, who had designed the engine of the 911, left to start a new career at Audi, and ended his professional life as the chairman of the Volkswagen Group. The other cousin, Ferdinand Alexander Porsche, who had designed the body of the original 911, started his own design studio. And one of the first clients of the studio was… Contax.

(**) – Contax launched its first autofocus film SLRs (the N1 and the NX) in 2000 with a new lens mount and a new series of lenses – roughly 15 years after anybody else. And followed up with the first full-frame dSLR in 2002, the Contax N Digital.  The products did not sell well and were rapidly withdrawn from the market, and Kyocera left the photography market for good in 2005. The Contax brand has been kept dormant ever since.

The lens mount of the Contax N, N1 and Nx of the early 2000s was totally different from the C/Y mount of this ST.  From an engineering point of view, the new lens mount was so close to Canon’s EOS that conversion jobs were possible. You can read a test of a converted lenses in Optical limits

More about the N series:

https://sunrise-camera.com/the autofocus-slr-camera-contax-n1

Luminous Landscape on the Contax N Digital


From the Contax ST brochure (available at: https://panchromatique.ch)

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La Grande Arche (Paris). From the Contax ST brochure (no photo credit). The brochure has been posted on https://panchromatique.ch