Vintage SLR cameras – the alternate mirror system of the Konica Domirex

The Konica Domirex was a prototype SLR camera which made its debut at Photokina in 1963. It had a very unique mirror mechanism, that effectively eliminated the need for the mirror to flip-up when the shutter release was triggered. The Domirex was a fixed-lens SLR with a 4-speed Seiko leaf shutter, and a Hexanon 57mm f/2.4 lens (but it actually looked like a rangefinder camera). The camera was described in US patent US3274912A, ‘Single-Lens Reflex Camera’, (1966, submitted 1962).

The concept was based on the idea of a beam-splitter reflex (BSR) which appeared in the mid 1960s [1]. Unlike an SLR which uses a mirror to reflect incoming light from the lens up through a pentaprism or waist-level viewfinder, the BSR deflects only a small portion of the light up through the viewfinder, with the remainder continuing on to the image plane. This was by no means a new concept, a similar idea had been used for a number of years in 16mm cine cameras – Bolex-REX and Arriflex 16.

Fig.1: The Konica Domirex

In the case of the Domirex it works in the following manner. Between the lens elements is a small optical block containing two small “asterisk-shaped” semi-reflective silvered surfaces, placed in the path of the light rays. These “mirrors” are fixed and inclined at 45° (these are off-axis, one to the left and one to the right), and carefully positioned so not as to cause issues with the exposed image. They send a portion of light from the lens to the roof prism, while the remaining light continues its trajectory towards the film. The roof prism takes up less space in the top of the housing but protrudes slightly towards the front, covering the upper part of the optical block. The camera also had both horizontal and vertical split-image rangefinders for focusing, and did not use ground-glass for focusing (which might have hindered the minimal amount of light passing through the viewfinder).

Fig.2: The beam-split reflex mechanism of the Domirex

Norman Rothschild reviewed the prototype in 1965 in Popular Photography [2]. The first thing he noted was “the one thing you’d expect to hear, is absolutely missing”, of course he is referring to the sound of the mirror. This design has the distinct advantage of not needing a large mirror that has to flip up in order for the light to pass through to the image plane during exposure. A large mirror causes mirror-black out, even if only for an instant, vibration, and of course noise. Get rid of the moving mirror, and there is no black-out, no vibration, and very little noise.

There were of course some inherent downsides to the design. As only a small amount of light is sent to the viewfinder, the viewfinder image would be much darker, than when 100% of light is reflected by means of a mirror. Could this loss of light have been a problem? Rothschild [2] suggested that the light loss was around 20%, meaning 80% of the light passed through to the image plane. But he seems to have had no problem focusing the camera, even in “relatively dim light”. This may be been due to the quality of the pentaprism, the lack of ground-glass, and split-rangefinder.

Fig.3: The Konica patent precursor to the Domirex

Perhaps the greatest problem would be the lack of interchangeable lenses. The prototype would have had to be modified to allow for interchangeable lenses. This could be accomplished by creating lenses incorporating the 45° reflective surfaces – but this would ultimately make them more expensive than traditional lenses. The camera also used a leaf-type shutter, which was certainly on the way out in the early 1960s, supplanted by the focal-plane shutter. By 1963 there was likely too much influence from existing SLR technologies to attempt to release a new technology. It is distinctly possible that as Mike Eckman suggests [3], the Canon Pellix, released in 1965, was a better option. It was a more conventional 35mm SLR, but with a semi-reflective mirror that accomplished the same aim as the BSR. But it offered a ground-glass, fully interchangeable lenses and a focal-plane shutter.

Rothschild though that the beam-splitting reflex design would eventually succeed in becoming part of the overall SLR market [2]. Rothschild’s final comment in the article was “the Dominex is worth waiting for, even if this takes a while.”. Sadly he would be wrong. Having likely made only prototypes, there aren’t many of these cameras about, however one of the original prototypes sold in spring 2024 for €12,000.

Further reading:

  1. Bill Pierce, “SLR’s Without Moving Mirrors: The Split-Beam System”, Popular Photography, 55, pp.64, 126 (June, 1964)
  2. Norman Rothschild, “Konica Domirex – A prototype”, Popular Photography, 54, pp.65-67 (June, 1965)
  3. Keppler’s Vault 47: Konica Domirex, Mike Eckman (2019)
  4. Konica Domirex

Are all prime lenses created equal?

The simple answer is no. One could argue that all 50mm lenses should do the same job, but from the perspective of image quality, nothing could be further from the truth. There are many reasons for this: the complexity of the optical formula, and its ability to keep optical deficiencies to a minimum, the quality of the glass, whether or not the housing is metal or plastic, whether or not the lens is automatic or manual… lots of things.

What I want to do in this post is provide some examples of how prime lenses differ (in the context of the Fuji-X system, although the same logic can be applied to any lens on any system). Let’s consider a series of lenses for the Fuji-X system with a focal length of 35mm, being the “normal” lens for APS-C size cameras, with a varied range of maximum-aperture values. The core characteristics are shown in Table 1, with the visual aspects such as lens design shown in Figure 1. Note that I have not included the sub-$100 category of cheap lenses, just because I don’t necessarily think they can be compared in the same manner (from the perspective of build-quality).

35mm (APS-C)Voigtländer Nokton f/0.9TTArtisan f/0.95Voigtländer Nokton f/1.2Fujifilm f/1.4 RFujifilm f/2.0 R WRMeyer Trioplan 35 f/2.8 II
aperturef/0.9f/0.95f/1.2f/1.5f/2.0f/2.8
aperture blades1210127912
weight492g250g196g187g170g270-300g
focusingmanualmanualmanualautomaticautomaticmanual
elements10/97/58/68/69/65
housingaluminummetalaluminumaluminumaluminumaluminum
country of originJapanChinaJapanJapanJapanGermany
priceC$2000C$300C$840C$800C$540€899
Table 1: Comparison of a series of Fuji-X compatible APS-C 35mm lenses

There are many things about these lenses that are very similar. The bodies are made of metal, they all weight roughly the same (except the Nokton f/0.9), the number of aperture blades is similar, and all bar the Fujifilm lenses use manual focus. Where they differentiate from a technical viewpoint is maximum aperture. From the perspective of design, most are based on some variant of the ubiquitous double-Gauss lens design. As shown in Figure 1, each lens is tailored to the specific “needs” of the manufacturer, augmented with specialized lens elements such as aspherical lenses.

The number one factor which differentiates lenses is usually price. Here native lenses are often more expensive than third-party ones, but not always. The most expensive lens comes from Voigtländer, the Nokton f/0.9, which is not surprising considering it has the largest maximum aperture, and is the most complex design, but also because Voigtländer is known for high precision optics. Voigtländer lenses are made by Cosina who make everything from scratch in its factories in Japan. For a slower lens there is the Nokton f/1.2 which is less than half the cost, but this is largely because of the lack of aspherical elements, and a simpler design.

Fig.1: Six types of 35mm lenses for Fuji-X

At the opposite end of the spectrum, is the TTArtisan f/0.95 lens which sells for C$300. Why the disparity? Likely less expensive manufacturing, or the lack of aspherical lenses. Many of these less expensive lenses seem to be based on older lens designs which have been improved in some manner. But the goal of Chinese lens manufacturers is to provide good quality optics at a reasonable price. Some of these cheaper lenses may also have some optical deficiencies, but this can be regarded as providing a “vintage” look in the way of creating images with character. For example sharpness at full aperture may not always be what one would expect. The TTArtisan 35mm f/0.95 has excellent bokeh, but does suffer from both vignetting on images with light corners, and lens flare at lower apertures.

Are these 35mm lenses created equal? Probably not, except perhaps in the context of providing the same angle-of-view. Their differences are varied, and can’t really be described in any meaningful way. We could compare them using 101 different tests, from measuring sharpness to the presence of optical artifacts such as chromatic aberration, but this is often a very qualitative endeavour. So which lens of this group is the best choice? Ultimately it comes down to budget, and personal preferences.

Note that this principle extrapolates out to most standard focal lengths.

Sense and nonsense

People expressing themselves in speech or writing are generally rather careful to avoid saying anything that might stamp them fools. Not so photographers, if one is to judge by the flood of trite and boring pictures published year in and year out in photographic magazines and annuals and shown in exhibitions. Using an analogy with speech, most of these pictures are as hackneyed as saying that a rose is a rose is a rose; they repeat what has already been said a thousand times before; they say badly what others have said better; or they say nothing at all, in which case they are visual gibberish, meaningless statements toward which a viewer’s reaction can only be, So what?

Andreas Feininger, The Perfect Photograph (1974)

Choosing an APS-C camera: 26MP or 40MP?

The most obvious choice when it comes to APS-C cameras is usually the number of megapixels. Not that there is really that much to choose from. Usually it is a case of 24/26MP or 40MP. Does the jump to 40MP really make all that much difference? Well, yes and no. To illustrate this we will compare two Fujifilm cameras: (i) the 26MP X-M5 with 6240×4160 photosites, and (ii) the 40MP X-T50 with 7728×5152 photosites.

Firstly, an increase in megapixels just means that more photosites have been crammed onto the sensor, and as a result they have been reduced in size (sensor photosites have dimensions, whereas image pixels are dimensionless). The size of the photosites in the X-M5 is 3.76µm, versus 3.03µm for the X-T50. This is a 35% reduction in the area of a photosite on the X-T50 relative to the X-M5, which might or might not be important (it is hard to truly compare photosites given the underlying technologies and number of variables involved).

Fig.1: Comparing various physical aspects of the 26MP and 40MP APS-C sensors (based on the example Fuji cameras).

Secondly, from an image perspective, a 40MP sensor will produce an image with more aggregate pixels in it than a 26MP image, 1.5 times more in fact. But aggregate pixels only relate to the total amount of pixels in the resulting image. The other thing to consider is the linear dimensions of an image, which relates to its width and height. Increasing the amount of pixels in an image by 50% does not increase the linear dimensions by 50%. For example doubling the photosites on a sensor will double the aggregate pixels in an image. However to double the linear dimensions of an image, the number of photosites on the sensor need to be quadrupled. So 26MP needs to ramp up to 104MP in order to double the linear dimensions. So the X-T50 will produce an image with 39,814,656 pixels in it, versus 25,958,400 pixels for the X-M5. This relates to 1.53 times as many aggregate pixels. However the linear dimensions only increase 1.24 times, as illustrated in Fig.1.

So is the 40MP camera better than the 26MP camera? It does produce images with slightly more resolution, because there are more photosites on the sensor. But the linear dimensions may not warrant the extra cost in going from 26MP to 40MP (US$800 versus US$1400 for the sample Fuji cameras, body only). The 40MP sensor does allow for a better ability to crop, and marginally more detail. It also allows for the ability to print larger posters. Conversely the images are larger, and take more computational resources to process.

At the end of the day, it’s not about how many image megapixels a camera can produce, it’s more about clarity, composition, and of course the subject matter. Higher megapixels might be important for professional photographers or for people who focus on landscapes, but as amateurs, most of us should be more concerned with capturing the moment rather than getting going down the rabbit hole of pixel count.

Further reading:

The APS-C dilemma

Should you buy a camera with an APS-C sensor, or a full-frame?

This argument has been going on for a number of years now, and still divides the photographic community. Is APS-C better than full-frame, or is it sub-optimal? Well, I think it’s all about perspective. APS-C, along with Micro-Four-Thirds are frequently viewed as mere crop-sensors, a designation that only exists because we perpetuate the falsehood that full-frame offers the “standard” sensor size. This stems from the fact that 36×24mm was the standard film size before digital cameras came along. As digital cameras evolved, “full-frame” became the name for the sensor size that matched a 35mm negative.

However we are at the point in time where each sensor size should be considered on its own merits, (and pitfalls) without unnecessary inference that it is a mere “stepping-stone” to a full-frame. Identifying an APS-C sensor, which has a size of 23.6×15.7mm, as “just a crop” sensor does not give the camera the kudos it deserves. The problem lies in every aspect of how these cameras relate to one another, but manifests itself best in lenses.

APS-C versus full-frame camera
The physical differences between APS-C and full-frame. The full-frame Leica SL3 is nearly twice the weight of the APS-C Fujifilm X-T50, and has a much bigger form factor.

Most APS-C sensors have a crop-factor of 1.5 (except Canon which is 1.6). This means lenses function a little differently than on full-frame lenses. Now a 50mm lens is always 50mm, regardless of the system it is associated with − it’s how that 50mm is interpreted in relation to the sensor that is important. For example a 50mm lens is a “normal” lens for a full-frame camera, while in APS-C land a normal is going to be a lens with a focal length of 33-35mm. A 50mm lens on an APS-C sensor will give a smaller picture than a full-frame, because well obviously the sensor is smaller. So an APS-C 50mm has the same effect as a 75mm lens on a full-frame camera in terms of what is in the picture.

Some basic visual comparisons of APS-C versus full-frame

There are obviously things that full-frame sensors do better, and things that APS-C format cameras do better. Image size is the first, which is purely the result of full-frame cameras having more photosites on their sensors. With the evolution of pixel-shifting technology this may be a mute-point as super-resolution images are already available on some systems. Full-frame cameras also tend to have better dynamic range and low-light performance. This is because photosites are often bigger on full-frame cameras, so they can collect more light and better differentiate between light intensities. This means they work better in low-light situations introducing less noise. But digital cameras rely on software to turn the data from photosites into the pixels in an image, and so as software improves, so too will things like noise suppression algorithms in APS-C.

How lenses function on APS-C and full-frame lenses

But not every full-frame has larger photosites. For example a Fuji X-H1 camera with a 24MP sensor has 6000×4000 photosites, with a photosite pitch of 3.88μm. The Sony a7CR has a 61MP sensor (9504×6336) with a pixel pitch of 3.73μm, which is actually smaller than that of the APS-C sensor. So more pixels, but perhaps a low-light performance that isn’t that much better. And what is anyone going to do with images 60MP in size? Post them on the web? I think not.

featureAPS-Cfull-frame
low-light performancegoodexcellent
depth of fielddeepermore shallow
lens availabilitylarge selectiongood selection, fewer third-party lenses
lens costaffordablemore expensive
portabilitylight, easy to carryheavy, bulky
dynamic rangeslightly reducedwider
applicationsstreet photography, sport, wildlife, travellow-light, studio, landscapes, portrait
camera body costtypically affordableusually expensive
wide angle lenses18-23mm28-35mm
normal lenses26-38mm40-58mm
A comparison of some of the characteristics of APS-C versus full-frame

Full-frame cameras, just like medium-format cameras are for people who need the things they provide – high resolution, low-light abilities, etc. Many people tend to correlate a full-frame camera with high quality because of its sensor size, but quality isn’t necessarily associated with high-resolution images. Yes, more data captured by a camera means more detail in an image, but that doesn’t automatically mean that APS-C sensors (or even MFT) are inferior.

Most non-professional photographers don’t need huge image sizes, just like they don’t need a Leica. APS-C cameras are considerably lighter, and more compact than their full-frame brethren. APS-C lens are also cheaper to purchase, because they are easier to build, and require less glass. In all likelihood there is also a broader ecosystem of third-party lenses for non-full-frame cameras as well, as they are cheaper to manufacture. Over time as newer sensors evolve, APS-C may be well positioned to take a more prominent role in the camera world.

Further reading:

Camera gear that amateur photographers should avoid

There is a lot of information about photography on the internet, and honestly for the beginner it can be overwhelming. The task of deciding on a digital camera is hard enough without content creators prattling on about things you probably don’t need. Here are a few pieces of gear to steer clear of – from the pure perspective of the amateur photographer.

Full-frame cameras − The ubiquitous dSLR, or “digital SLR” is an extension of 35mm film cameras, hence the reference to “full-frame” (sensors are 36×24mm). They have been the mainstay of professional photographers for the past two decades. But they are not something that an amateur photographer should even consider. They are large, heavy, and prohibitively expensive. The size alone makes them inconvenient for things like long-term travel. In an age of mirrorless cameras with good APS-C sensors they honestly just don’t make a lot of sense. Even the big manufacturers such as Nikon have shifted their emphasis away from dSLRs. There are situations where dSLRs are more of an advantage – low light, a larger sensor, wildlife an sports photographer, none of which are really the concern of the amateur photographer.

This Sony 50mm lens is fast, but it is too much lens for the beginner

Fast lenses − What is a fast lens? I would probably categorize it as a lens with a speed faster than f/1.8 up to f/1.2. They contain a lot of glass, are heavy, and expensive. But frankly most people don’t need these lenses. They are perfect for people who shoot a lot at night, or in low-light settings, but slower lenses can also be used in these scenarios. (I wrote a whole post on whether you Should you buy a superfast lens?, and Are modern ultrafast lenses useful?)

Super telephoto zooms − The zooms offer focal lengths like 100-500mm, and are very versatile, just not for the beginner. It’s tempting to consider, but not actually that useful unless you have a specific need, i.e. sports and wildlife photography. In many cases it is just too much zoom. For example landscape photography doesn’t always gel well with focal lengths beyond say 200mm, because there is a tendency to loose perspective, which is the whole point of many landscapes. The other problems are pretty obvious – size and weight. Of course here there is another benefit of mirrorless APS-C cameras, smaller zooms. The Tamron 150-500mm lens for Fuji-X seems amazing (225-750mm eq.), but it contains 25 elements, and weighs 1.71kg – try lugging that around for an extended period!

The Tamron 150-500mm super telephoto zoom – a behemoth for amateurs

Filters − There are a lot of really good filters which do things like reduce glare, and unwanted reflections, and correct or enhance colours. For example polarizing filters are useful when shooting landscapes in sunny locales, they darken skies, and make colours stand out more. Neutral density filters reduce light hitting the sensor, but doesn’t affect image colours. But it may be best to focus on taking good photographs, and conquering exposure before adding filters into the fray. P.S. UV filters are basically pointless because most sensors aggressively filter UV light. Save the filters for when you gain a little experience.

Tripods − Most people do not need a tripod. They are super useful for taking stills at home, or when you need to use a super-slow shutter speed, but otherwise they are a bit of a door-stop. They are not at all useful for travel, and overall just aren’t worth the effort. The only ones that can be somewhat useful are the mini variety such as the Manfrotto PIXI (but honestly avoid the Gorilla-type flexible tripods).

Camera body upgrades − Avoid the trap of upgrading your camera body every 1-2 years. A camera body should last a good amount of years, so there really is no need to consistently upgrade. If you are at the point of considering which camera to buy, save some money and buy an older version of the camera. The reality is that technology has plateaued somewhat in digital cameras, and there isn’t going to be much difference between two or three generations of a camera (except the price). Advanced features aren’t that useful if you are still grappling with the basics.

A light meter − If you have a film camera, then a light meter might be a must. But in the case of digital cameras, having a dedicated light meter may not be necessary. Good ones are expensive, and take up room. It’s easier to trust the light meter in the camera, or for film cameras use a light meter app such as Light Meter Ultra.

Lenses you don’t need − It’s hard not to want all the lenses that photographers review online. They look cool, and it would be fun to play with them right? Especially the myriad of inexpensive lenses now on offer. But here’s the thing, most of them you won’t use on a regular basis. Fish-eye lenses are a good example. They are fun and creative because they provide an ultra-wide view of the world. But the caveat is that reasonably priced ones are typically manual focus, and there are very few applications (unless it is a rectilinear fish-eye). There is probably a good reason that manufacturers like Fuji don’t have any fish-eye lenses.

Photography can get to be an expensive hobby, and buying things you don’t need can be a slippery slope. Many of these things I learned the hard way. Buying lenses that I thought I would need, but ended up sitting on a shelf. Think of it this way – every piece of gear that you buy should solve a problem of some sort, but not just a 1-2 instances, a problem you encounter a lot. If you are really interested in a lens, then try and rent the lens before buying to actually see if it is as useful as you think.

Ultimately a new lens or any other gear doesn’t replace the need for knowledge and experience, or frankly will it help you do something if you don’t really know what you are doing.

What happened to the Zeiss lens collection?

When Carl Zeiss Jena was still under US control in June 1945, the US Army Signal Corp’s Pictorial Division expropriated the “Zeiss lens collection”, which consisted of approximately 2000 sample lenses, and associated documentation. The collection was handed over to Colonel Tebov on May 12, 1945 in Jena.

The collection represented not only Zeiss lenses, but optics from other manufacturers, and was used in research and production control. The lenses were transferred to the Signal Corps laboratories at Fort Monmouth, and the documentation to Dayton-Wright Army Air Field in Ohio. At Fort Monmouth, chief of the photographic branch (Signal Corps Engineering Laboratories) Dr. Edward F. Kaprelian, studied the lenses, attempting to understand and recreate the optical designs in many of the prototype Zeiss lenses. Supposedly the lenses were to be analyzed, in particular several hundred experimental lenses that were never sold. None of these historically and technically significant lenses had been clearly documented as part of the appropriation. Willy Merté, head of optical computation at the former Carl Zeiss Jena was apparently languishing in a refugee camp in Heidenheim before Carl Zeiss could begin operation in Western Germany. Merté would go on to catalogue the collection.

In April 1947, Popular Photography was the first major US publication to give a two page sneak peek [1]. Example lenses described include:

  • The Spherogon, a 1.9cm f/8 lens with a plano (flat) front element 3” in diameter, with an AOV of almost 160°.
  • The R-Biotar, was the fastest commercially produced lens in the world, at 4.5cm with an aperture of f/0.85. It was used for 16mm movies of fluorescent x-ray screens.
  • The Bauart BLC, a 20cm f/6.3 objective used by the Luftwaffe for aerial mapping.
  • The Perimetar 2.5cm f/6.3 for 35mm cameras, covering a 90° AOV with a deeply concave front element.

Probably the best description of some of the more unusual lenses comes from a June 1947 article by Kaprelian himself [2]. In it he describes some of the V (versuch) or experimental lenses. He describes lenses like the V1940, a 7.5cm f/2.8 lens with a 70° AOV, with little astigmatism or coma, and very little in the way of distortion. Or the V1935, 10cm f/6.2 lens whose front element is strongly concave. Another lens already produced in certain quantities was the Sphaerogon, available in focal lengths from 1.6 to 12cm and f/7, f/8 apertures. Other lenses include experimental aspherical surfaces, telephoto, and wide-aperture lenses.

Where are these lenses today? Perhaps stuck in a storage locker somewhere in the vast storage facilities of the US Army? Well, actually no. In an article in Zeiss Historica in 2016, the fate of the collection is documented [3]. Stefan Baumgartner bought a number of lenses from the collection in 2006, and as he tells it, this is when a major portion of the collection was put up for sale on eBay, a legacy of the estate from American photographic businessman Burleigh Brooks. Apparently after Kaprelian’s release from his military service the collection was left in the custodianship of Burke and James in Chicago, occupying warehouse space for about 20 years. It was later disposed of as military surplus, which is why Brooks probably acquired some of the lenses (as he owned Burke and James).

Further reading:

  1. Walter Steinhard, “Lens Oddities”, Popular Photography, 20(4), pp.82-83 (1947)
  2. Edward K. Kaprelian, “Recent and Unusual German Lens Designs”, Journal of the Optical Society of America, 37(6), pp.446-471 (June, 1947)
  3. Stefan Baumgartner, “A Mystery of Another Lens from the Zeiss Collection”, Zeiss Historica, 38(1), pp.17- (Spring, 2016)

Vintage lens makers – Zunow (Japan)

Zunow was a lens maker who dabbled in camera making. Their biggest claim to fame is arguably that they were the first to introduce an ultrafast 50mm lens for rangefinder cameras. Supposedly the meaning of Zunow derived from the Japanese word zunō meaning “brain” (although there was also a Zunow company producing bikes where it meant “genius”).

Suzuki Sakuta founded Teikoku Kōgaku Kenkyūjo (Imperial Optical Research Institute) circa 1930 and worked for other companies grinding lenses. In 1954, the company changed names to Teikoku Kogaku Kogyo Kabushiki Kaisha (Teikoku Optical Industry Corporation), and in 1956 it became Zunow Kōgaku Kōgyō K.K., or Zunow Optical Industry Co. Ltd..

Fig.1: Various lenses produced by Zunow

Zunow made a number of lenses for both rangefinder and SLR cameras, including slower 50mm lenses in f/1.3, and f/1.9, a 35mm f/1.7, and a 100mm f/2 lens. In 1953 they introduced a 5cm f/1.1 lens for rangefinder cameras, which at the time was the fastest lens available for any 35mm camera. The f/1.1 lens was not matched in speed until Nippon Kogaku introduced the Nikkor 50mm 1.1 in 1956. After this they started making lenses for other manufacturers, which weren’t as fast, but they were good quality lenses. For example the 35mm f/1.7 was a smidgen faster than the Nikkor 35mm f/1.8. The lenses were often used by other manufacturers as standard lenses. A good example is the Miranda T which came standard with a Zunow 50mm f/1.9 lens. There is some supposition that Zunow supplied the 5.8cm f/1.7 lens for the Yashica Pentamatic II when it appeared in 1960 [1].

Fig.2: Lens configurations of various Zunow 35mm lenses

The first cine lens was a 5cm f/1.1 lens produced for American motion picture camera company Mitchell. The company also produced Zunow-Elmo Cine f/1.1 lenses for D-mount (8mm) in 13mm, 25mm, 38mm; and C-mount (16mm) 25mm, 38mm and 50mm.

Fig.3: Zunow lenses can be found on Neoca cameras, as fixed lenses with leaf shutters; and on Nikon rangefinders

The decline of Zunow was precipitated by the failure of its Zunow SLR in 1959, and by the bankruptcy of two of its customers – Arco in late 1960 and Neoca in January 1960. Zunow’s financial situation worsened, and rather than become a subsidiary of another company, the company was closed in 1961 [2]. In the same year, Suzuki Takeo founded a new company in partnership with Elmo (who Zunow had supplied lenses for) called Ace Optical who continued making lenses for 8mm and 16mm cine cameras, as well as other commercial lenses [2].

Besides the 5cm f/1.1, other lenses are available, especially in the Japanese market. The cine lenses seem to sell anywhere from US$200-1000. The 3.5cm f/1.7 rangefinder (L39) lens has sold for around US$3500. Typically they are found mostly on the Japanese market.

Fig.4: Zunow packaging and advertising

A list of lenses produced in 1957:

  • Rangefinders (Leica IIIf and M-3, Contax Canon, Nikon) : 35mm f/1.7, 50mm f/1.1, 50mm f/1.3, 50mm f/1.9, 100mm f/2.
  • 35mm SLR : 50mm f/1.9, 100mm f/2
  • 8mm cine : f/1.1 – 13mm, 25mm, 38mm
  • 16mm cine : f/1.1 – 25mm, 38mm, 50mm

Company name timeline:
1930 − Teikoku Kōgaku Kenkyūjo (Imperial Optical Research Institute)
1954 − Teikoku Kogaku Kogyo Kabushiki Kaisha or Teikoku Optical Industry Corporation
1956 − Zunow Kōgaku Kōgyō K.K., or Zunow Optical Industry Co., Ltd.
1961 − Company closes, re-envisioned as Ace Optical the same year

Notable lenses: Zunow 5cm f/1.1 (1953)

Note that there is still an unrelated company called Zunow in the north of Japan, which makes conversion lenses and filters (for cine cameras).

Further reading

  1. Was this beautiful lens, which was made exclusively for the Pentamatic II designed by Zunow Optical?, Chasing Classic Cameras with Chris (2017)
  2. Interview with Suzuki Takeo, CEO of Ace Optical (son of Zunow’s president), May 2006

Ultrafast lenses – the Zunow 5cm f/1.1 (and 58mm f/1.2)

The 1950s photographic industry in Japan was marked by a race to develop the fastest lens. In December 1950, Nippon Kogaku, maker of the Nikon, would introduce the Nikkor 50mm f/1.4, the fastest normal lens produced. But the victory was short lived, as in 1953 an even faster f/1.1 lens was introduced by a little known company – Zunow.

Fig.1: Literature in Japanese news announcing the f/1.1 lens

The development of the Zunow 5cm f/1.1 began in 1943 at the Teikoku Optical Co. to meet the high-speed optical needs of the Japanese Navy [2]. There was a requirement for a fast lens in low-level light situations such as aerial surveillance at dawn and dusk. The design was spearheaded by Sakuo Suzuki, and Michisaburo Hamano (NY Times, Nov.21 1953), and managed to produce three prototypes, but the factory was destroyed in a raid late in the war. It would take ten years to complete the lens. The first prototypes were completed in 1950, and the 50mm f/1.1 was Zunow released in 1953.

Fig.2: Lens diagram from the patent with associated optical glass types

The patent for the Zunow f/1.1 lens [3] describes the lens as “an improved photographic objective suited for use with a camera that takes 36×24mm pictures”. The lens had a configuration of 9 elements in 5 groups, in a Sonnar-type design, likely derived from the Sonnar 50mm f/1.5. It was available in mounts for Contax, Nikon and Leica rangefinder cameras. The amazing thing about this lens is the fact that it was not constructed using any “rare earth” glasses.

Fig.3: Comparison of lens diagrams for Sonnar f/1.5, and the two versions of the Zunow f/1.1 (hatched lines indicate new glass) [2]

The original version earned the nickname “Ping-Pong ball” because it featured a rounded end. However it faced some issues, mostly when the aperture was wide open, e.g flare. Kenji Kunitomo and Yoshitatsu Fujioka would join the company to address these issues. This lead to the introduction of the Type 2 in 1955. The new design dealt with the protruding ball structure by redesigning the lens. It was transformed into a flat rear design with 8 elements in 5 groups, which also dealt with the flare and brightness issues when wide open. The lens elements featured a hardcoating on all air-glass surfaces to reduce internal reflections [7].

Fig.4: Specs for the original 1953 lens

Comments on the lens performance in The Truth About Superspeed Lenses (1957) [4]:

  • Performance: Vignetting at the widest aperture f/1.1, disappears completely at f/2.8. The lens is acceptably sharp at the centre of the negative. Detail is lost toward the edges and corners. Sharpest range is f/5.6 to f/11.
  • Comments: The Zunow lens mount may cut off the right corner of some camera viewfinder windows, blocking part of the image. It might be a good idea to use an accessory viewfinder with the Zunow. We found it an easy lens to focus quickly.
Fig.5: The “Ping-Pong ball” lens

While the Zunow 50mm f/1.1 lens was the first ultrafast lens for rangefinders, there were few if any lenses of equal stature in the SLR realm. Ads at the same time showed a Zunow 58mm f/1.2 fast lens for Exakta and Pentacon SLR cameras. While very few have seen this lens in real life, and it does not appear to have been sold at any auctions in recent memory, there is a glimpse into what it looked like in the one of the ads for the Zunow camera shown in Figure 6. It was apparently a 7 element/5 group lens, of some expanded double-Gauss design [6]. The 58mm f/1.2 would have been the fastest lens offered by any camera manufacturer at that time for an SLR. In all likely so few were made that they today sit in private collections.

Fig.6: An ad for the 50mm f/1.1 lens, and a sneak peak at the 58mm f/1.2 in a Japanese ad for the Zunow SLR

Nevertheless, it would take Nippon Kogaku until early 1956 to match the Zunow lens in speed, introducing the Nikkor 50mm 1.1. Canon was not in the picture until the 50mm f/0.95 in 1961, and Leitz not until 1976 with the Noctalux 50mm f/1.0. The Zunow 50mm f/1.1 is today a vary rare lens. Sales are are US$5-10K, up to US$20K depending on condition, and mount. The price for this lens in 1956 was US$450, although it could be found for as low as US$300.

Fig.7: The Zunow SLR showing the 58mm f/1.2 lens, and its 7/5 configuration

Further reading:

  1. Norman Rothschild, “Meet the Zunow f/1.1”, Popular Photography, pp.126/128, February (1956)
  2. Kogoro Yamada, “Japanese Photographic Objectives for use with 35mm Cameras”, Photographic Science and Engineering, 2(1), pp.6-13 (1958)
  3. U.S. Patent 2,715,354, Sakuta Suzuki et al., “Photographic Objective with Wide Relative Aperture”, August 16, (1955)
  4. “The Truth About Superspeed Lenses”, Popular Photography, 21(10) pp.62-64 (1957)
  5. Zunow Teikoku Kogaku Japan 50mm f1.1 – The First Ultra Fast Lens
  6. Tsuneo Baba, “Zunow: Indication of things to come in 35mm single-lens reflexes?”, Modern Photography, 23(4), p.110 (1959)
  7. “New f/1.1, 50mm Zunow Lens”, Popular Photography, 20(5) pp.26,30 (1956)
Fig.8: The 50mm f/1.1 lens in various guises

Vintage SLR cameras – the Alsaflex, a French SLR

This is a story of another camera that could have been quite successful, but unfortunately didn’t make it past the initial batch of cameras. Alsaphot was the photographic department of a French company called Alsetex, and produced cameras from 1949 to 1970. Using a brand logo which incorporated an Alsatian stork, the company produced a broad range of cameras. This included the Dauphin I, II and III, small 6×6 reflex cameras in the style of the Voigtländer Brilliant and the Cima (4×6), Ajax (6×6), and D’Assas (6×6) viewfindser cameras.

In 1947 the company hired French inventor Lucien Dodin (1900-1989) as technical director. Dodin designed two cameras, the Cyclops, and Alsaflex. The Cyclops, which appeared in 1950 was a 6×9cm format camera. Dodin’s claim to fame was the design of the “stigmometer”, or Dodin telemeter, more commonly known as the split-image rangefinder, something found in many SLRs.

Fig.1: The aesthetically pleasing Alsaflex

The Alsaflex was an SLR camera which used the 24×24mm format on 35mm film, and incorporated Dodin’s stigmometer. The viewfinder was reduced in size by using lateral reflection, the retractable mirror pivoting around a vertical axis – essentially a Porro prism. The camera was innovative because it was quite compact for an SLR. It sported a bayonet mount with interchangeable lenses, with a Saphir Boyer 40mm f/3.5 (with automatic aperture selection) as the standard lens. The shutter was of a new design, made of metal and in the shape of a fan, with speeds from 1 to 1/2400 sec. The body of the camera was die-cast (150mm×70mm×42mm) with a back that could open to accommodate carious accessories. The camera has a rapid lever actuation which causes the film to advance, the mirror and the frame counter to be set up, and the shutter to cock in a single movement. When activated during shutter release, the mirror retracts without vibration.

Fig.2: Advertising the camera that never really made it big

A second variant, the Dudragne is a special, much simpler model of the Alsaflex, without a horizontal viewfinder eyepiece, X-sync and 1/100 speeds, and made to be used with a retinograph (instrument for examining the retina of the eye) made by Dudragne. Interestingly, the license for the viewfinder using the Porro prism would be taken over in 1963 by Olympus for the Pen F series. The camera appeared in advertising in early 1950, suggesting it would be released in May 1950, but in reality it would be 1952, and very few would be produced. It was advertised as having an “optically coupled rangefinder independent of the focal length of the lens”.

Alsaphot itself declined in the 1960s with the rise of both German and Japanese imports. In 1954 the Alsaflex with a Saphir Boyer 50mm f/2.8 was advertised for 138,000 Frs or about C$384 [1]. When the occasional camera go on sale, the price is generally in the range of €3000-5000.

  1. In January 1954, 1 Canadian $ equals about 360 Old French Francs.