Schacht was founded by Albert Schacht in 1948 in Munich (Germany). Albert Schacht had a long pedigree of lens design. From 1913-1919 he was an operations manager at Carl Zeiss Jena, followed by seven years at ICA A.G., before it was merged into Zeiss Ikon (Dresden) where he continued until 1939. During the war years until 1946 he was a technical director at Steinheil in Munich. Schacht focused on designing and building lenses for 35mm film cameras. In 1954 production was moved to Ulm. Schacht manufactured interchangeable lenses in the range of 35-200mm for all common camera connections. Most lenses at Schacht were designed by Ludwig Bertele, who founded an optics office in Switzerland in 1946 with the help of Wild Heerbrugg.
The first interchangeable SLR lens manufactured was the Albinar, 13.5cm f/4.5 in 1952. It was produced exclusively for export to the USA and with an Exakta bayonet connection. It wasn’t really a telephoto, but rather just used a simple 4-lens design. Production was then expanded to include three more common focal lengths: the Travenar 50mm f/2.8, 85mm f/2.8, and 135mm f/3.5. The Albinar was renamed Travegon in 1954. They were available in Alpa, Exakta, Praktica (M42), Pentacon, and Leica mounts. In 1956 a wide-angle Travegon 35mm f/3.5 was introduced. Schacht produced lenses in the most popular focal lengths, and was one of the first lens manufacturers to deliver SLR lenses with an automatic aperture.
Fig.1: Advertisements from Schacht
Most of its early lenses were of standard 1950s aluminum construction. In the 1960’s Schacht changed the visual appearance of their lenses to match those of other manufacturers, i.e. a black lens with a zebra-style design which initially incorporated berg-and-tal stype controls, opting eventually for a more modest raised style of grip. These are generally considered good quality lenses, however not as common as other brands. Early lenses are marked as A. Schacht Munchen, older ones A. Schacht Ulm. Brands included: Albinar, Travenar, Travegon, Travelon, Travegar, Travenon, sometimes with the prefix tele- S-, M-, or Tele-.
Fig.2: Schacht changed their design over the years from an aluminum aesthetic to black with a zebra-style look.
In 1967 the company was acquired by Constantin Rauch. In 1969 the optics division was sold on to the Wilhelm Will KG company in Wetzlar. Due to production difficulties, lens production ended in 1970.
When you look at modern lenses, there isn’t much that sets them apart. They are usually pretty plain black cylinders, partially due to the consistency of modern lens design. The same could not be said of vintage lenses. Maybe this has something to do with the fact that many vintage lenses were made by companies that focused purely on lenses, and as such tried hard to differentiate their lenses from their competitors. For example a company like Meyer Optik Gorlitz manufactured lenses for cameras using the Exakta mount had to compete for the consumer spending with lenses from a myriad of other companies (at least 25-30).
Over time the appearance of lenses naturally changed, as new materials were introduced, often for the purpose of reducing the overall cost of lenses. For example, many early 35mm lenses had a shiny, chrome-like appearance. The earliest, pre-war lenses were often made of chrome-plated brass. As the Second World War progressed, shortages or re-direction of materials like brass led some manufacturers had begun to transition towards aluminum, which was both less expensive, easier to manufacture, and produced a lighter lens. While these early aluminum lenses were aesthetically pleasing there was little that differentiated them in a world where there was an increasing number of 3rd party lens manufacturers.
Fig.1: Evolution of the aluminum design of the Zeiss Jena Biotar 58mm f/2
When it first appeared as a lens material, aluminum was chic. The 1950s was the age of aluminum, which was a symbol of modernism. Many of the largest aluminum producers pursued new markets to absorb their increased wartime production capacity, used in everything from drink cans to kitchenware and Airstream trailers (there was also extra aluminum from scrapping of war surplus aircraft etc.). These aluminum lenses were initially clear-coated to reduce the likelihood of tarnishing, but eventually anodized to provide a robust black coating. Also in the 1950s, lens manufacturers to realize changing trends in lens design – buyers had moved away from the idea of pure practicality, and focused also on design. This wasn’t really surprising considering the broad scope of modernist design during this period – design tended to favour sleek and streamlined silhouettes. It is interesting to note that most of the aesthetically pleasing lenses of the post-1950 period originated from Germany.
Fig.2: Every lens manufacturer had a different interpretation of both “berg-and-tal”, and the black-and-white “zebra” aesthetic
The first notable change was the gradual move towards what in German manufacturers called the “berg und tal” design, or rather “mountain and valley” design of the grips on a lens – usually knurled depressions milled into the surface of the ring (but also the opposite like the lenses of Steinheil where the depressions are smooth and the mountains are knurled). English-speaking regions often referred to this as a “knurled grip”. Appearing in the early 1950s, it was particularly common for focusing rings, making them more prominent, and likely more ergonomic, i.e. easier to grip. Some lenses started with the focusing ring, and eventually used the same design on the aperture ring. Prior to this most lenses used a simple straight knurl on the adjustment rings.
Towards the end of the 1950s, the pure-aluminum design transitioned to a combination of silver and black anodized aluminum. The lens bodies themselves were mostly black, with the “berg und tal” designs alternating between black and silver. This alternating pattern is what is colloquially known as “zebra” design. Many lens manufacturers utilized the zebra aesthetic in one form or another including Schacht, Enna, Steinheil, Schneider-Kreuznach, Meyer Optik, Rodenstock, ISCO etc..
Fig.3: Meyer Optik had an interesting twist on the zebra design. There were very few of these lenses and they are very minimalistic in design.
Zeiss probably produced the best known examples of the zebra aesthetic design with the Pancolar and Flektogon series of lenses. Although these lenses did not appear until the early 1960s, they bypassed the more prominent berg-und-tal in favour of a much subdued black-and-white knurled grip (which is also something Meyer Optik did with lenses like the Lydith 30mm). This design for both focusing and aperture rings replaced the rough textured rings of the earlier lenses. Some call these lenses the “Star Wars lens”. The Pancolar 50mm f/2 appeared ca. 1960 in the form of an f/2 lens with dual black-silver body encompassing a “converging-distance” depth of field range indicator, and either a textured or nubbed rubber focusing ring. This evolved a few years later to the classic “zebra” design, shortly before the release of the classic Pancolar 50mm f/1.8, which also sported the zebra design. By the 1970s, the Pancolar 50mm f/1.8 had morphed into a complete black configuration with a large rubber cross knurling focus grip and a finely knurled aperture ring.
Fig.4: Evolution of design aesthetics of the Zeiss Pancolar 50mm lens.
Japanese manufacturers transitioned from aluminum/chrome to black bypassing the zebra design. The one exception seems to be the Asahi Auto-Takumar 55mm F/1.8, which appeared in 1958, but is the sole example of zebra design (at least by Asahi). Japanese manufacturers did however embrace the berg-and-tal design.
Fig.5: Some lens companies couldn’t settle on a design. Here we have differing focus ring designs from the same Meyer Optik catalog in the 1960s
By the mid-1960s many camera manufacturers were producing their own lenses, particularly in Japan. As such lenses became more consistent, with little need to compete with other lens manufacturers. There were still 3rd party lens manufacturers but their perspective was to concentrate more on the manufacture of inexpensive lenses. Most lenses transitioned to using standardized, nonchalant black aluminum lenses, with the onus being more on the quality of the optics. Grips transitioned from berg-und-tal to a flatter, square-grooved style, still using a in black/chrome contrast (which likely resulted in a cost saving). By the mid-1970s focus rings were provided with a ribbed rubber coating, still common today on some lenses.
Fig.6: Berg-und-tal overkill?
Fig.7: One of the few Japanese zebra lenses.
Today, the sleek aluminum lenses are sought after because of their “retro” appeal, as too are the zebra lenses.
Vintage “normal” lenses most often range from 40mm to 58mm, although the greatest number of theses lenses fall in the range 50-58mm. A lens which satisfies the ideal of being “normal” has a focal length close to the diagonal of the film format. So, 24×36mm = 43mm. 35mm is an exception to this rule – when Oskar Barnack developed the original Leica he fitted it with a 50mm Elmax to ensure the most could be done with the small negative area. From that, the 50mm became the ubiquitous standard. With the proliferation of 35mm single lens reflex (SLR) cameras, manufacturers in the early years tended to fit 55-58mm lenses. But why was this the norm instead of 50mm?
There are a variety of reasons. Let’s start at the beginning.
When Ihagee (Dresden) released the worlds first 35mm SLR in 1936 it had a series of standard lenses, but basically there were two categories: the slow 5.0cm lenses which ranged from f/2.8 to f/3.5 (e.g. Tessar, Xenar), and the marginally faster, 5.0cm/5.8cm f/1.9-2.0 lenses, e.g. the 5.8cm f/2 Biotar (developed for the Exakta). The first post-war Exakta did not appear until 1949, the Exakta II, along with a cornucopia of standard lenses from numerous manufacturers, but the fastest 50mm lens was still the Zeiss Tessar f/2.8.
The “… to 60-mm…” was included in the normal-lens category only because such lenses are frequently supplied as standard optics on single-lens reflexes. The reason is that in many cases the designers have found it easier to meet the special requirements of through-the-lens focusing by going to a slightly longer focal lens. Fifty-eight mm is the most common choice.
Bob Schwalberg, “Interchangeable lenses by the carload”, Popular Photography, pp.36-38,197 (May, 1956)
The 35mm SLR experienced a rapid increase in popularity among amateur photographers in the 1950s, especially after manufacturers realized that the installation of a prism viewfinder made handling this type of camera much easier. With this came the need for faster lenses, for two reasons – the ability to take pictures in poor lighting conditions, and a brighter viewfinder image makes it easier to focus. Lens such as the Biotar 58mm f/2 were considered to have a long focal length – to the amateur this was less than favourable, because they would get less coverage than 50mm. Over the course of the 1950s, manufacturers worked on new lens configurations to increase the speed of 50mm lenses, however 55mm and 58mm lenses still maintained the edge in terms of speed.
Fig.1: The two fastest pre-1950 35mm normal SLR lenses. Note the angle-of-view (horizontal) between 50mm and 58mm is not that different.
The original Asahi Takumar lenses which evolved with the 1952 Asahiflex (M37 mount), only included a single 50mm lens, with a speed of f/3.5. Both the 55mm (f/2.2) and 58mm (f/2.2,2.4) lenses had faster speeds. The 58mm f/2.4 in 1954, which became the standard lens for the Asahiflex II. The Auto Takumar’s focused on 55mm lenses with both f/1.8 and f/2.0 lenses. It was not until the Super-Takumar’s appeared in 1964, that the fast 50mm became more normal, with the f/1.4 lens. Canon didn’t produce much in the way of fast SLR lenses until the FL series lenses, introduced for the Canon FX, and FP, which debuted in 1964. Here there was a fast 50mm f/1.4, yet the f/1.2 lenses were still in 55mm and 58mm. In truth, even 50mm lenses faster then f/1.8 did not appear in Japan until the mid-1960s. many of the super-fast 50mm lenses were developed for rangefinder cameras, and never extended to SLRs.
The post-war German 50mm lenses did not really get much faster than f/1.8. This is in part because although the competition in Japan spurned a lens “speed-war”, the same was not true in Germany. The fastest lenses of the early 1950s was still the Biotar 58mm f/2, and Meyer Primoplan 58mm f/1.9. By 1960, at least for the Exakta Varex there was now a 50mm f/2 in the guise of the Zeiss Pancolar. By 1962 Exakta brochures had sidelined the Biotar 58mm, in favour of the Meyer Optik Domiron 50mm f/2. The Japanese had however established f/1.8 as the standard speed for a 50mm. The Zeiss Pancolar 50mm f/1.8 is an extremely good lens, but did not appear until 1964. Similarly the Görlitz Oreston 50mm f/1.8 did not appear until 1965. One of the reasons these “average” speed lens were produced is volume. The production of Praktica cameras in the mid-1960s reached 100,000 units per year, all of which needed a standard lens. It was all about economics.
Fig.2: Speed milestones in 55/58mm and 50mm lenses. Note that while a 50mm f/1.2 lens for rangefinder cameras existed as early as 1954, it would not be until 1975 that one appeared for 35mm SLRs.(note that the diagram may not represent every possible lens)
It was not the same in the world of 35mm rangefinder cameras. There was already a fast pre-war lens, the Zeiss Sonnar 50mm f/1.5 (7 elements/3 groups). The original Sonnar was designed with six elements in three groups, which would allow a maximum of an f/2 aperture. In 1931, a redesign with a new formula was developed with seven elements in three groups, allowing a maximum aperture of f/1.5. But the problem with the Sonnar design was that for shorter focal lengths, e.g. 50mm, it had a short back-focal-distance (BFD) which although being an advantage in rangefinder cameras, made them incompatible with most SLR cameras due to the space taken up the (retracting) mirror (which increases the flange focal distance). The set-up is illustrated in Figures 3 and 4. In Figure 3, the lens is shown how it would normally appear in a Contax rangefinder camera. However if the same lens were used in a 35mm Exakta (Figure 4), there would be an issue because the BFD would be too short because of the increase length of the flange focal distance, which is due to the clearance needed by the mirror.
Fig.3: Lens to film on a Sonnar 50mm f/1.5 lens attached to a 35mm Contax rangefinder
Fig 4: Lens to film on a Sonnar 50mm f/1.5 lens superimposed on a 35mm SLR.
This illustrates the biggest problem with making a fast 50mm lens was the fact that the addition of a mirror in the SLR meant that lenses had to be further from the film plane, requiring a redesign of the optical formula of the lenses. The easier solution was to marginally increase the focal length.
Trying to adapt the Sonnar design to 50mm was probably cost prohibitive as well. The Sonnar’s had large glass elements with massive core thickness, which required very thick sheets of raw glass, and they had strongly spherical lens surfaces. The latter issue lead to more issues when cementing lenses together, i.e. it was time consuming and required great precision. The Tessar 50mm’s on the other hand could be produced much more efficiently which made them less expensive to produce. The only real Sonnar design for SLRs was produced by Asahi, the Takumar 58mm f/2 from 1956 (6 elements/4 groups).
Partly to more easily provide clearance, for the moving mirror, and partly to produce a larger viewing image, the post-pentaprism wave of SLRs got off to a slow start in the early fifties with 58-mm standard lenses. Since physiological factors dictate an eyepiece of approximately 58mm focus, the choice of this focal length for the normal lens gave a 1-1, fully life-sized viewing image.
Bob Schwalberg, “The shifty fifty”, Popular Photography, pp.73-75,118,119 (Sep., 1970)
Some of the reasons were likely simpler than all that. When Carl Zeiss released the Contax S, the world’s first 35mm production SLR camera with an eye-level prism viewfinder and exchangeable lenses in 1949, the camera came with the Biotar 58mm f/2 as the kit lens. The popularity of the Biotar, spurned others to adopt a similar lens design. One of the reasons the Biotar had a large following was because it was felt that it provided a deeper and more three-dimensional image. There were many Biotar types of lenses, but at 58 mm the image in the prism finder had approximately the same scale as one viewed with a naked eye. Last but not least, as we have seen in a previous post, 58mm approximates the 30° central symbol recognition of the HVS, which means it quite nicely fits into the scope of focused human vision.
Aside from mechanical issues, there may have been other more aesthetic reasons for the 55mm/58mm lens frenzy. There is an experiential rule that says a portrait lens for half-body portrait should be about 1.5 times the focal length of a “normal” lens (2 times for head-shots). If we take the normal range to be about 40-55mm, this would make an appropriate lens about 60-82.5mm. So a 58mm lens is quite close to the minimum for half-body portraits. No surprise that the upper bound is also close to 85mm, a favourite with portrait photographers. Why did this matter? Because of the large market for amateur photographers in the 1950s who were interested in taking pictures of family etc.
The trend of 55/58mm lenses had reversed itself by the mid-1960s, with 50mm lenses becoming faster likely due to the advent of faster glass, and better optical formulae.
A lens that has been stored in an inappropriate environment, i.e. one that is dark and humid, may provide the perfect conditions for the growth of fungus. Fungus takes the form of tendril or web-like structures on the surface of the lens. The fungus secretes an acid that etches a lenses’ multicoating. This sort of damage can be permanent, and hard to remove. Too much fungus will lower contrast, and way too much will give darker, fuzzier images as it blocks light. Fungus is bad news – avoid lenses with it, however small the “infection”.
⑥ Yellowing
Coatings on lenses often yellow in time. Glass in general does not yellow, but lens coatings, or at least older ones do. This is also true of glass made with radioactive elements, e.g. Thorium, to reduce refraction.
⑦ Bubbles
Some lenses pre-1970 had defects caused by the optical glass manufacturing process which left a few pin-prick sized air bubbles inside the glass. These bubbles may come from different sources, but in most cases the source is imperfect refining. They look like tiny dust specks when viewed with the naked eye, but if magnified, they are indeed bubbles.
⑧ Separation
Lens groups are most often held together with some type of glue. In modern lenses this is usually a UV-cured epoxy. Vintage lenses typically use epoxy, polyester, and urethane-based adhesives, and some pre-WW2 lenses use Canada balsam (basically a resin from balsam fir trees). The balsam was used because it has a refractive index that is similar to crown glass and is invisible when dry. Unfortunately, Canada balsam is not resistant to temperature extremes or solvents. A degradation of the adhesive will result in the lens delamination. This usually manifests itself as a multicoloured band or blobs around the edge of a lens with coatings, or a white band/blobs on lenses with few or no coatings (but it can also occur in the centre of a lens). A small amount of separation on the edges of a lens will likely have little effect on image quality. A large amount may cause a decrease in contrast, flare and ghosting, softer edges, loss of sharpness, and a difficulty in focusing.
Fixing anomalies
Is it possible to rectify these optical defects? The table below provides a quick guide, and later posts will explore some of these defects in more detail.
Defect
Repairable?
Lens disassembly required?
Notes
scratches
maybe
no
It is hard to remove scratches, especially deep scratches, although fine scratches might be able to be buffed or polished out (some people suggest toothpaste).
haze/fog
yes
yes
It might be possible to use a cleaning solution to reduce or suppress the haze.
dust
yes
yes/no
Dust on external lens surfaces is easy to clean. Internal dust is harder because it requires lens disassembly.
blemishes
no
no
Multicoating damage cannot be repaired.
fungus
maybe
yes
It is possible to repair low levels of fungal infections, but it does require lens disassembly. Heavy fungal infections are not repairable.
yellowing
yes
no
Yellowing caused by the presence of Thorium can be reduced using UV lights.
bubbles
no
no
Intrinsic to the lens glass, consider it a feature of certain older lenses.
separation
no
yes
Separated lens groups are basically not fixable. Fixing these requires lens separation, re-centering and re-cementing.
There are a number of physical anomalies that can be found on the optics of vintage lenses. Regardless of the abnormalities of the lens body, the critical part is the optics. Sometimes people classify lenses as “a little rough”, or “needs some attention”. These can be red flags. Note that when shopping for vintage lenses in person, take an LED flashlight along as it will help peer inside the lens to determine if it is fit for use.
① Scratches
Glass doesn’t scratch that easily, but coatings do. Scratches are easy to detect, because they usually occur on the visible, exposed glass elements. Scratches usually occur on the front or rear element of a lens. They signify obvious signs of wear, or possibly damage. Small scratches will have little effect on an image, but deep scratches will. A few small scratches on the front element will not impair performance significantly – the reason is the depth of field generally works to negate their impact. The exceptions are macro lenses and wide-angle lenses. A large number of tiny scratches may also reduce the contrast of a lens. Scratches on the rear lens will be more problematic (it is best to avoid lenses with scratched rear elements). Because there is less distance between the element and the sensor/film, most scratches will appear on the resulting picture. Deep scratches can be a sign of severe trauma. Also check for pitting. Sometimes lenses have light scratches which are caused by poor lens cleaning/polishing techniques.
② Haze or fog
Haze can be anything that settles out of the air inside the lens onto the inner surfaces of the glass. The lubricants on the aperture mechanism and in the focus threads can vaporize over time and then resettle onto the glass, and with enough time other things (dust, salt-air, fungus) can get in and collect on the glass, to the point that they are dense enough to refract the light themselves and spread it around as a “foggy” look to pictures. Haze actually gets worse with age. This may be an indication that the lens was poorly constructed, or poorly stored.
A smoky haze diffuses light equally over the entire image. This is generally caused by trillions of particles much smaller then the wavelengths of light, smearing the light over all areas equally, simply making blacks gray and reducing the overall contrast. Oily haze on the other hand has tiny droplets larger than the wavelengths of light. Because the oily haze diverts light, the haloes are much stronger and more visible.
③ Dust
Dust particles somehow get into lenses. A small bit of dust will make little or no difference to image quality. Larger specks or clumps of dust should be avoided. Check for dust by shining a light through the lens. Dust may be especially prevalent in vintage zoom lenses where the increased movement can result in dust infiltrating the inner components of the lens. So how does dust get inside the lens? Vintage lenses are not air sealed, i.e. weather sealed, meaning that air moves in and out, and of course it carries dust with it. Zoom lenses with barrels that extend out essentially “pump” air/dust into the core of the lens. In reality, small amounts of dust will impede very little of the light passing through a lens, and its impact on the image quality is minimal. Inexpensive and simple lenses can be easily disassembled and cleaned, however re-assembling the lens may again introduce dust (unless you have a clean room). Large amounts of dust may be indicative of poor long-term storage.
④ Blemishes
Many vintage lenses have lens elements that are coated with layers of some non-reflective optical material. These multicoatings minimize light reflection and the resulting lens flare and ghosting. Blemishes are regions on a lens where material has been smeared or removed by physical damage, a manufacturing defect, use of an incorrect solvent, or even being eaten away by fungus. A small blemish likely won’t affect image quality.
A lens with a super-deep scratch. Being on the rear element, this will effect the image.
The state of a lens can tell a lot about how it was previously treated. There are many different aspects to choosing a vintage lens. One important aspect is physical condition. There are a number of things that cause a lens to lack perfection, some you can overlook, while others could indicate a lens should be avoided. Don’t forget these vintage lenses are anywhere from 30-75 years old, and they will not be in pristine condition (or if they are you will pay a premium). A lens may be pristine from an external viewpoint, but have issues with the aperture or focusing mechanism. Or it may be completely functional, yet be aesthetically distraught.
There are several different levels of lens examination. Obviously in an ideal world you could slot the lens on a camera and take some pictures, however that isn’t always feasible, and deep testing isn’t really an option in a store. Sometimes lenses are only available in online stores, so you have to rely on the quality of the stores vetting processes. The tests described below look at the physical properties of a lens, and does not test the optical characteristics by shooting test pictures. Please note that obviously if you are buying online, you cannot physically check the lens. And therefore must rely on the lenses quality being properly described. If buying online, purchase from a reputable shop. Note the 🕸️ symbol used below refers to hints for online purchasing.
① Lens body defects – scratches and dents
No vintage lens will be in perfect condition, unless it has sat in its box stored away somewhere and never been used (the so-called “new old-stock”). The first thing to check is what the lens looks like externally. Many vintage lens bodies are largely constructed of metal which has a tendency to scratch and dent. Scratches on the lens body are usually not that big a deal, dents are another matter altogether. Usually a dent will typically occur at either end of the lens, and can signify that the lens has been dropped. Some lenses are of course built like tanks, and can withstand a drop better than others. Damage to the lens mount will make it almost impossible to mount the lens. Conversely damage at the thread end will mean an inability to mount a filter (it means either replacing the front component, or for a minor issue using a lens vise to restore the thread).
Fig.1: Various types of physical damage to a lens
A dented filter ring is usually the result of a lens falling and landing on the front edge which could mean the lens elements have been knocked out of alignment. Lens bodies made of plastic will also scratch, however dropping them will likely cause more damage. It is also possible that a lens can lose coating, through abrasion or chipping. This is common in old chrome-plated lenses, as shown in the sample photograph in Figure 2.
Fig.2: More types of physical damage including the loss of coating on a lens body.
🕸️ A series of photos covering all aspects of the camera will help determine the shape it’s in.
② Movement of lens parts
Vintage lenses are composed of several different cylinders that move when the aperture or focus ring is activated. The first thing to do when testing a lens is to check it by gently moving the components, extending the segments, and rocking the whole lens. Basically this helps determine if any of the sections are loose, or if there are any loose components rattling around inside the lens. Next look to see if all the external screws are present, and if the front ring accepts a filter. Visible markings such as stripped screws might be indicative of disassembly/reassembly and internal issues in the past. Loss of some paint or wearing of rubber parts isn’t usually a problem.
③ Lens mount
The mount should be checked, firstly for compatibility, but also for damage. The mount can be checked by mounting it on an appropriate mount converter. It should go on easily, yet firmly, without any looseness. Does the locking pin catch properly? Check that a mount actually exists for converting the lens to a digital camera. For example some lenses such as the E. Ludwig Meritar 50mm f/2.9 were made for Altix cameras which have a breech-lock type mount, which is hard to find adapters for.
🕸️ A snapshot of the rear of the lens helps document the lens mount, which is especially important for less common lens mounts.
④ Aperture mechanism, i.e. diaphragm
Testing the aperture is a necessity, if the aperture on a lens is not performing well, it will feel loose and not well connected. An aperture that is slow to open or close may signify issues with the aperture mechanism. If the aperture mechanism does not move the aperture blades at all, there are serious issues. The number one thing to check is to make sure the aperture actually opens and closes smoothly (sometimes the aperture ring moves, but the diaphragm blades do not). Other things to check depend on the type of mechanism:
Manualmechanism – The simplest mechanism involves the aperture ring turning from the fully open position (smallest f-number) to the closed position (largest f-number).
Aperture pre-set mechanism – The pre-set ring should be set to the closed position, and then the second ring which closes the aperture should be rotated. Also make sure the pre-set ring rotates freely.
Auto-aperture mechanism – This mechanism uses a device that leaves the lens aperture open for as long as possible, and closes the aperture to a set f-stop simultaneously with shooting. In order to check the aperture, depress the pin of the mechanism, then rotate the aperture ring from open wide to closed. The diaphragm should open-close without issue.
⑤ Aperture – iris blades
Apart from the free movement of the diaphragm (iris) blades, the other thing to check for is whether they are dry or oily. Iris blades should be clean and dry – they do not require lubrication. Some aperture blades may appear oily which means it will be hard for them to open and close in a smooth manner. When oil is present on the aperture blades, there is friction from the oil’s viscosity and this impedes the quick closing action during exposure. The aperture takes too long to stop down, and as a result the shutter has already activated, and the photo can become overexposed. Where does the oil come from? An oily aperture is typically caused by exposure to heat. The focus mechanism of a lens uses lubricants, and heat can causes these lubricants break down, and to leak.
Fig.3: Oily iris blades in a Kilfitt Tele-Kilar 300mm
The best way to determine the state of the blades is to view them from the front by flashing an LED flashlight into the lens and look down on the blades. Oil will appear as a circle, or small triangular “wings”. A patterned discolouration is a sure sign of oily blades. Play with the aperture ring to check its “snappiness” – it should open and close easily without resistance or a feel of “sticking”. Dry blades are certainly better, but there are certain lenses (e.g. Helios) that are not greatly impacted by the presence of a small amount of oil. Some aperture blades may also have rust on them, this could be indicative of the lens being stored in a sub-optimal environment, e.g. one that is humid.
⑥ Lens focus mechanism
Rotate the focus ring back and forth a few times from the minimum focusing distance (MDF) position to the opposite (infinity) position. The focusing ring by itself should rotate smoothly, without hesitation or any sticking. A focus that is overly tight can lead to improper focus, whereas a loose focus means the focus can shift with the slightest move. What we are looking for here is whether or not the lens moves smoothly and doesn’t catch or have a gritty sensation. A stiff movement may be indicative of issues with the grease used to lubricate the focusing mechanism. Are there any dull spots where the focus mechanism doesn’t feel as smooth or gets slightly stuck? This might mean degrading grease and could need to be repaired. Make sure the focus doesn’t stick slightly at either extreme. If the focus ring doesn’t move at all, then it is likely the grease lubrication has solidified to the point where it is stopping movement.
⑦ Lens markings
It may seem trivial, but lens markings are important in identifying a lens. This information includes manufacturer, trademark, focal length, maximum aperture, coatings (e.g. multi-coating). See the post on lens markings. 🕸️ A snapshot of the front of the lens often means a serious reseller. A poor or unreadable picture suggests that reseller does not know how to sell the lenses and most likely an amateur.
⑧ Lens body defects – dirt, grime and corrosion
If a lens seems dirty and grimy, it may be indicative of how well the lens wasn’t cared for. Dirt and grime usually appear in textured surfaces which are subject to being hand-manipulated, such as the focus ring. Oil and sweat (from the skin) are deposited when these regions are touched and subsequently attract dirt. Failure to clean a lens will mean a built-up of grime over time. This dirt may eventually migrated to the interior of the lens by means of nearby lens openings. Sometimes vintage chrome-plated lenses appear green, and this is something commonly known as “green corrosion”. This can be the result of corrosion of the brass/copper underneath the chrome (chrome surfaces typically have a underlay). As brass contains copper, the copper reacts with oxygen, forming the greenish-blue layer, copper-oxide.
Fig.4: Dirt, grime and corrosion
If the outside of the lens looks and feels okay, then it is time to investigate the optics.
In a 1956 copy of Popular Photography, there was an article on the German lens maker Kilfitt. In the article, reference was made to a 180mm f/1.9 lens called the Grand-Kilar… there was even a picture. But did this lens actually exist? Well according to vague literature, it appeared in 1955, a 4-element lens, designed by A. Burger. But brochures of the early 1960’s show nothing in the way of 180mm lenses. It does appear in various editions of Arthur Cox’s “Photographic optics” in the 1960s, however searching the net does not seem to yield anything in the way of tangible proof to suggest any exist today. Perhaps very few were actually manufactured. In comparison the to SLR, it seems like a massive lens for the period.
We now look at a fast telephoto lens – the Zoomatar 180mm f/1.3. This lens may have been a natural successor to the Grand-Kilar, the lens that seemingly never was. It was produced in the period after Zoomar Inc. took over Heinz Kilfitt. It is one of the fastest lenses above 100mm.
It was one of two super-fast telephoto lenses produced by Kilfitt in the 1960s, the other being the Zoomatar 75mm f/1.3. Both were intended for use in cinematography, with the 180mm also able to cover the 36×24mm area of normal SLRs. It seems like the 180mm lens was designed with the sole purpose to allow a maximum amount of light in, and it had the proportions to justify this – it was 250mm in length, had a diameter of 166mm, and weighed an astonishing 7kg – heavier than their Reflectar 1000mm f/8.
Kilfitt Zoomatar 180mm f/1.3
It has an optical scheme with six lenses, with a large difference between the diameter of the front (140mm) and rear (31mm) elements. Interestingly, because this lens was a cinematographic lenses, there is also some data on light transmission. Supposedly the light transmission was 80%, giving a T-stop of 1.5. Unlike the 75mm lens which was only supplied in C-mount, the 180mm lens came in various film formats (16mm and 35mm cine), in addition to 35mm. This means the angle-of-view could range from 3° on 16mm film to 7° on 35mm film. In 2011, one of these lenses sold on eBay for US$10,480.
Super Zoomatar 240mm f/1.2
Considering it sold in the mid-$2000’s in the 1970s, I don’t imagine many were actually manufactured (I have seen estimates of between 50-70). Zoomar did however create an even faster lens, relative to focal length – the Super Zoomatar 240mm f/1.2 – it was a behemoth at 11kg. It was originally developed for instrumentation cameras and for use with image intensifier tubes.
On the heals of the Biotar 75mm f/1.5, I came across a posting for a Biotar 70mm f/1.4 in a Leica L39 mount. Was this a real lens? The serial number of the lens is 2620709, and it was selling for ca. C$78K. The serial number suggests it was produced in 1939.
This is a strange lens because there is very little information regarding its provenance. CollectiBlend suggests only 116 lenses were produced between 1929 and 1939. Most seem like they have been adapted to mounts such as M42. The early 1930s Zeiss catalogs do specify a 70mm f/1.4 lens, however it is for cinematographic work, specifically recommended for 40×35mm format. By the late 1930s they were also being advertised for miniature, i.e. 35mm cameras. This was however not advertised for use with either Contax 35mm camera offered by Zeiss-Ikon, which advertised a 85mm as a portrait lens.
Early brochure information on the Biotar f/1.4
According to the catalogs of the period, there were a series of f/1.4 Biotars, in 2cm, 2.5cm, 4cm, and 5cm focal lengths in addition to the 7cm (70mm). The Biotar initially played virtually no role at all for still image cameras. In fact one of the most numerous Biotars produced at that time was the Biotar 2.5cm f/1.4 which went into production in1928. By the end of WW2, just over 1,300 units had been manufactured, most of which were delivered to Bell & Howell or Kodak, but also to Siemens, among others. The Biotar 4cm f/1.4 was created as a medium focal length for 18×24mm standard film cameras – the format used in 35mm cine cameras.
Dating based on serial numbers: 2620709 (1939) and 950044 (1929-30)
Now I have seen three different versions of this lens, none of which really meshes with the descriptions found in early catalogs – here the lenses are cited to a mount diameter of 60mm, and come in either an “N” mount (for cameras with bellows extensions), or an “A” mount (for folding and other hand cameras). The few lenses available today are in the form of re-housed optics, i.e. the lens has been adapted at come point to fit mounts like the Leica mount. Some of these lenses were made for “miniature” cameras, and so some may actually have native LTM mounts.
Not every fast vintage lens is a 50mm. Sometimes others are fast in relation to their focal length, like the Carl Zeiss BIotar 75mm f/1.5, considered by some to be the original ‘King of Bokeh’. The lens has a reputation for creating an incredible picture, which can be partially attributed to its ability to produce amazing bokeh, which was not exactly something that was mainstream in the mid-decades of the 20th century.
The Biotar lenses were designed in 1927 by Willi Merté (1889-1948) for cine cameras (Patent No. DE485,798). Merté continued developing the Biotar lenses, and in 1938 introduced the Biotar 75. Construction was complete by April 1938, and the lens went into production in February 1939. It was quite radical for the time, especially considering that all calculations for these systems were performed manually, i.e. by humans. It is often the reason very few of these lenses changed their specifications. The lens is a 6-element, 4-group, Double-Gauss optical design.
The first copies were made for cinematography, followed shortly after for Ihagee’s 35mm Kine Exakta. The advent of WWII meant that few lenses were sold, and those sales were likely restricted to lens enthusiasts who could afford them. Based on the available literature, it doesn’t seem like any were exported from Germany. In 1943, competition arrived in the form of the Leitz Summarex 85mm f/1.5. The design was a 7/6, but was prone to flaring, and heavier, at 700g to the Zeiss’s 500g. Post-war more competition in the German market resulted in the Meyer-Optik Görlitz Primoplan 75mm f/1.9; the Enna-Werke Ennaston-Lithagon 85mm f/1.5, and the Carl Zeiss Jena 85mm f/2 Sonnar. By the mid 1950s there was also competition originating from Japan.
“The ultra-light intensity of the 75mm ‘Night Lens’ ensures adequate exposures even under the most adverse lighting conditions, i.e. theatre, circus, cabaret, and night life. As this particular lens is more than three times as fast as the 2.8 lens, successful pictures can be obtained in towns and cities, illuminated only by normal street lighting.”
Exakta Varex IIa brochure, 1958
The three Biotar 75mm variants
There are three known variants of this lens. The first pre-war variant is known as the “skinny” Biotar 75. Introduced in 1938, this version has a thin, compact barrel. It was supposedly made of brass with a chrome-plated finish (although it is likely this changed to aluminum during the war). This lens were predominantly made for the EXA mount (not surprising considering the Exakta was the prominent 35mm SLR of the period). Early versions did not have an anti-reflection coating on the glass surface, which could cause flare when shooting against the light. Coatings, marked with a red “T”, began to be applied during the war (possibly for the military).
Carl Zeiss Jena Biotar 75mm f/1.5 Ver.1
After the war, Zeiss-Ikon was to release the Contax S, which used the M42 screw mount. Zeiss redesigned many of their lenses to take on the M42 mount. This resulted in the second version of the lens, produced between 1946 and 1952. This lens made use of lanthanum-containing Schott glass for its lens elements. This version was made in East Germany. Starting with this model, aluminum was used for the lens barrel to reduce weight. Additionally, the minimum aperture has been changed to allow up to f/22. In this variant, mounts for M42, Leica (L39), and Praktina were added, and it was compatible with at least five types of mounts, including those for Exakta and Contax. All have the “T” coating, although it may not be marked with a red “T”. Around 1950 markings were changed from 7.5cm to 75mm. The distance scale is a single one, which is very easy to read.
Carl Zeiss Jena Biotar 75mm f/1.5 Ver.2
The third version of the lens was produced from 1952-1968, as is known as the “fat” Biotar 75. This version has a solid barrel with a knurled/scalloped focus ring, a double distance scale, i.e. numbers on either side. The diaphragm is now preset, and the minimum aperture is back to f/16.
Carl Zeiss Jena Biotar 75mm f/1.5 Ver.3
The lens had various names over the 1950’s based on where it was sold. The lens was known as Nachtobjektiv Jena B (Night-lines Jena B), Zeiss-Biotar, “Jena B”, or just Biotar.
The lens is truly a pivotal design, it was not until new types of glass were designed, and the advent of computer-aided optical development that further progress could be achieved, ultimately leading to the Zeiss Pancolar 75mm f/1.4 in the mid-1960s. The 75mm lens itself would not really feature in the future of lenses, supplanted by the 80mm and 85mm focal lengths. Over its 30 years in existence, only roughly 20,000 copies were made. Supposedly they were made in very small batches (100-200) due to the nature of the lens – the optical elements required large pieces of flawless glass.
Zeiss specs for the “fat” version
In the early 1950s, the lens sold in the USA as a “high speed lens”, for around US$216, which is US$2,500 in 2023 based on inflation. In Germany in 1953, this lens sold for DM596 (which when converted was cheaper than in the USA (US$141). Today these lenses sell anywhere from US$2000-6000+ depending on condition, and variant. An alternative, which honestly costs a whole lot less, is the modern Biotar 75 f1.5 II, from Meyer Optik Görlitz (it sells for €1400, ca. C$2000).
NB: You can always tell when a Zeiss lens was manufactured from the serial number.
Crafting Pixels 