- Travel on my time-machine
- The known Facts – Topcor 30cm f/2.8
- Topcor 30cm f/2.8 – Optical Performance
- The Reference: Canon EF 300mm f/2.8 IS USM
- Three more 300mm f/2.8-teles
1. On my time-machine:
I own the Topcor R 30cm f/2.8, which I am looking at here, since a few years – but I have not used it too often. It is very heavy, long and dark, giving the impression of a tank-breaking weapon: you definitely will get trouble at any security check nowadays … and in the best case you will earn compassion instead of admiration! Too bad, because it is an ingenious piece of optical engineering.
Information about Topcor lenses today are rare and not always reliable. I will restrict myself to reliable information and I will try to verify legends … or destroy them.
So I entered my time machine and travelled back into the year 1958. I was 13 years old at my arrival there – and at the Topcon (Tokyo Kogaku) factory I met a team of innovative engineers, who were fanatically burning for the QUALITY of their products – and really proud of it! The year before (1957) they had introduced a new SLR-camera (Topcon R), which was designed in Bauhaus-style, i.e. with clear and modern lines – and they were ready to ignit a firework of innovations around the SLR-concept within the next few years (from first-in-industry TTL-exposure-metering to first electric winder).
And they had introduced a line of lenses for this SLR-system-camera, among which the Topcor 30cm f/2.8 peaked out. Another „first-in-industry“-innovation.
I looked around in the photo-stores and could not find any Canon- or Nikon-SLRs there: the dealers told me, that both companies were just bringing out SLRs. It seemed, that the Topcon-people had considered the German SLRs, which were already on the market, as their competition. Personally at that time I was already a SLR-user (of my father’s Contaflex – which means, that from time to time my father was still allowed to use it himself).
Everybody, who is acqainted with the rules of the market, would have expected, that shortly after an innovation like the Topcor R 30cm f/2.8, the major competitors would bring out a similar product.
But that did not happen – so I returned in my time-machine. Finally I found out, that it took the new japanese competitors more than a decade! And there was no comparable Lens in Europe, as far as I could see. 13 years later Nikon presented a prototype, to be tested during the Olympic Winter Games of Sapporo in 1972.
The real next step was taken by Canon with a 300mm f/2.8 Lens for their new FD-System, using a lens made of FLUORITE in 1973 (some say 75)! This was finally 16 years after the arrival of the Topcor-lens … and just in that year, when Topcon stopped the production of their supertele-lens.
2. The known facts:
This Topcor R 30cm f/2.8 monster-tele-lens with 300mm focal length was presented to the world in 1958 („Topcon Club“ says 1957!) – one year before Canon or Nikon started to produce any SLR – and 13-16 years before any other lens- or camera-maker presented such a fast 300mm tele-lens. Not only at the 1964 Olympic Games in Tokyo but all the time until 1972 it was without any competition. As a consequence, there even was produced quite a number of lenses with Nikon mounts! Next to Topcon, Canon brought out its Canon FD 300mm f/2.8 S.S.C. Fluorite lens in 1973 – setting the level for professional superlele-lenses for the next decades and until today. Just a few years later Topcon went completly out of the business with SLR-cameras and lenses. Sad, but even the extensive book „Topcon Story“ by Marco Antonetto and Claudio Russo (1) does not answer the question „why?“. Today Topcon is a market-leader in geodesic instruments.
Stephen Gandy (3) estimates – cameraquest.com – that 700-800 lenses have been produced in total during 18 years of production.
The lens is made of six single lenses in four groups – of which lens no. 6 (group 4) is the filter (diameter 39mm), which is, of course, part of the optical design! This filter is an early (maybe the first) example of a filter which is positioned in a slot in the rear part of the lens-body. In the book „Topcon Story“ (page 128) there is an error in the spreadsheet listing of the data of the R.Topcor-lenses: the data in the last line are the data of the „300mm 2.8“ and not of the f/5.6-lens. Here the no. of elements is „five“, which is correct, when you don’t count the filter as an active optical member …
The lens has a preset diaphragm and has a built-in sunshade (telescoping in two stages!). It is 383 mm long (from camera-flange to front-edge of the pulled-back sunshade – total length with shade pulled out is 477 mm) and weighs 3.1 kgs (without front and rear caps). Measured at my sample (ser. no. 34.1359). The initial sales-price was $ 1.125,–. (In the literature you will find: 415/412 mm length and 3.3 kgs weight).
It may be interesting to mention here, that right away from the introduction of the first Topcon-SLR, an extremely ambitious lens-program was planned – however, realized only partly. The Topcor R 13,5 cm f/2.0 (6 lenses) had also preset diaphragm and it was discontinued with the Topcon RE camera system – so it is said to be extremely rare. It has a yellowish color cast (due to rare-earth-glass?), not a big problem with todays digital cameras …
However, a 50mm f/0.7 lens, which is mentioned in „Topcon Club“ only, was never made for the SLR-camera market – maybe, this was one of the very early oscilloscope-registration-lenses, which are also known from Germany and GB even at WWII-times.
And a 1000mm f/7 catadioptric lens was only experimentally made in 1958.
„Topcon Club“ (2) writes about this:
„The interchangeable lenses which appeared with the appearance of TOPCON R are various kinds of the Auto Topcor of 35mm/100mm, and R TOPCOR (a preset diaphragm) of 90mm/135mm/200mm/300mm among these – although the bright thing and the dark thing were prepared about 135mm and 300mm – it should mention especially – it is the „high-speed lens“ of 135mm f2 and 300mm f2.8. 50mm f0.7 – such a bright lens was already completed during wartime by the Tokyo optics. Do you believe it ? Although possibly this grade was an easy thing, even so, the 300mm f2.8 lens will be an astonishment thing in 1957. I talked in detail on „the page of TOPCOR“ about this lens. We have to wait for marketing of the product of NIKON which is the next 300mm f2.8 lens at any rate till 1977. However, TOPCON did not build the super telephoto lens 500mm /800mm those days. Furthermore, the Refrector Topcor 1000mm f7 is appearing in the catalog in ’59. However, this was not launched regretfully.“
Later – from 1969 on – a RE Topcor 500mm f/5.6 telephoto-lens was even produced with automatic diaphragm and meter coupling!
Can such a fast long telephoto lens like this early 300mm f/2.8-design without Fluorite- or ED-lenses be any good – on the scale of professional photography? There are hints, that rare-earth glasses were used to make these lenses (also for the other famous 13,5cm f/2.0, also supplied since 1958). But I do not know details about this.
I will answer the question about the optical quality here – also comparing this lens with a modern top-notch tele-lenses like Canon EF 300mm f/2.8 L IS USM, which I personally classify as today’s state-of-the-art reference, supported by photo-friend Thomas, who borrowed his Canon lens to me.
Finally I will take a glance on a state-of-the-art modern astronomical refractor, which normally does perform at diffraction-limited resolution on stars!
Topcor 30cm f/2.8 – The Optical Performance on analog film (year 1969):
Stephen Gandy (3) wrote in his blog:
WIDE OPEN its resolution was 56lines/mm center and 34lines/mm at the edges. By f/8 it was 80 lines/mm center and 65 at the edges. Many normal lenses don’t achieve this sharpness — much less 300/2.8 leviathans ! Camera 35 summed it up by saying „INCREDIBLY FANTASTIC.“ I would have to agree. „
(In the original text in Stephen’s blog, the reported resolution values are noted as „56mm“ or „34mm“. I have taken the freedom, to correct this to what it should read: lines per mm, „lines/mm“!)
The resolution values, which I use in my digital IMATEST measurements, typically are given in „Line-pairs per picture-height“ = „LP/PH“. Picture-height being 24mm with 24×36-format, you have to divide the „lines/mm“-values by two to get to „line-pairs“ – and then multiply with 24 to achieve LP/PH.
The highest given value of 80 lines/mm corresponds to 960 LP/PH stopped down to f/8 in the center or 760 LP/PH at f/8 at the edge – the lowest value 34 lines/mm with open diaphragm at the edge corresponds to 408 LP/PH.
What does that mean?
In 1969 the test results for resolution were measured on film – „Modern Photography“ used Plus-X Pan with standardized development – and the reading of the „just resolved“ line-pattern was done with a standardized enlarging glass … I personally used the method myself at that time, too, and it is quite reproducible as long as the same person does the reading … It is somewhat sensitive to the vision-capabilities of the reading person! And of course the grain of the analog film material (negative b&w film!) is the limiting factor for the resolution-reading on film for really high resolutions.
Today’s modern 24 MP-sensors deliver resolutions of 2,000-2,400 LP/PH using MTF30 (30% contrast) as the parameter for reading out the resolution values from the MTF-curve. My Sony A7R4-Camera (62 MP), which I use for my measurements, has a Nyquist frequency of 3.168 LP/PH and delivers up to 3.800 LP/PH-readings with the best known lenses.
The following spreadsheet gives an overview on the physical data of the Topcor-lens and the other lens-monsters, analysed here:
3. Topcor 30cm f/2.8 – Optical Performance
My IMATEST-Results of the optical properties of the Topcor R 30cm f/2.8 lens:
To exclude potential vibration-initiated degradation of resolution in my test-shots at these long focal-lengths I used my heavy (>10 kgs) and sturdy astronomical telescope-mount:
Following you see the results of my IMATEST-measurements:
The lens is unique at that time regarding to „speed“ – an extremely ambitious piece of optical engineering. Remind, that the distortion is practically zero and the CA-area in the center 0,8-1,4 pixel – 1 pixel at Sony A7R4 is 3,8 microns on the sensor!
What is center, what is part way and what is corner? In the following graphs from IMATEST you see: „Part-Way“ is the large part of the picture extending close to the narrow side (left/right). „Corner“ is the narrow area outside the second dotted circle on the picture below.
So, let’s compare the measurements to the value, that were given in analog times on film:
The comparison in the spreadsheet Fig. 10 shows: The lens „out-resolves“ normal analog films by far! Stopped down it reaches the limits of the analog medium even at the edges of the frame!
I found no real technical explanation, how Topcon-engineers managed to generate this phantastic lens at that time without ED/LD/AD/Fluorite-glass. There is a second tele-lens – the 13,5cm f/2.0, also introduced 1958, with first-in-industry potential – and finally the Topcor 2,5cm f/3.5 super-wide, which surprises with best-in-class resolution values (see my blog-article on historical 24/25mm-lenses!).
If somebody knows the secret: please, tell us!
Look at a sample picture taken with the Topcor at the end of this article at 65% enlargement size (see Fig. 24).
Now, let’s have a glance on some other historical Superteles:
4. The Reference: Canon EF 300mm f/2.8 IS USM
Canon EF 300mm f/2.8 IS USM is rated as the reference of this class of lenses. In this case it is not the latest „Mk II“-version of it, which came out 2011 – but the first version of 1999, which is tested here. It represents nevertheless already the top-class of the super-teles (as all its predecessors since 1973!)
Here are the IMATEST results of its optical properties:
And here the Graphs of resolutions center, part way and corner:
Not may comments necessary to this – the figures and graphs should speak for itself … Just to mention: the distortion at the Topcor-lens is even lower than that of the Canon – but both are neglectable for a supertele!
Canons leadership in this class of professional supertele-lenses was generated by the policy, not to drop a product into the market, which was „just possible“ at present, but to persue a consequent plan for the future: to solve the „secondary spectrum“-problem of long tele-lenses, which means to use extreme „anormal dispersion“ lens-materials, which do the job without optical compromising.
So in 1975 – 2 years after Nikons first presentation of its first 300mm f/2.8 ED-lens (which was not very convincing and had to be replaced four years later by the ED-IF-version) – Canon introduced their FD 300mm f/2.8 Fluorite-Supertele, in which they used a front-lens made of fluorite-monocrystal material (no glass!) and a UD-glass-lens. This lens was already praised close to perfect (absence of chromatic aberrrations). Canon accepted for this a compromise, which made the lens longer and heavier: to protect the soft and sensitive fluorite-crystal-material in the front lens, there was a fixed additional plane protection element of glass in front!
Finally new fluorite-glass-formulations became available, which allowed to drop the sensitive crystal-lens. Over the introduction of Autofocus (EOS – 1987) and still more glass-elements, Canon finally introduced the legenday lens EF 300mm f/2.8L IS USM in 1999 with very fast AF and image-stabiliser, which is tested here.
Enjoy the results!
5. Finally – three more 300mm f/2.8-teles:
- Minolta AF APO-Tele 300mm f/2.8 (1985)
- Tamron SP LD (IF) 300mm f/2.8 (60H) (1984)
- ARSAT MC Yashma-4H 300mm f/2.8 (1990?)
For these three lenses I also have to thank foto-friend Thomas, who borrowed them to me!
5a. Minolta AF APO-Tele 300mm f/2.8 (1985)
This lens had a mechanical defect: the diaphragm could not be closed below f/5,6. However: in these lenses principally mainly the open aperture is really significant – why should you carry around such a weight, to make pictures with f/11?
This Minolta lens comes closer to the Canon-legend than any of the others – but with quite some distance in resolution in the corners open aperture.
5b. Tamron SP LD (IF) 300mm f/2.8 (60B) (1984-1992):
This is the shortest and lightest lens of the quintuple, which arrived even one year before the Minolta – containing two low-dispersion (LD) lenses – with manual focusing:
Tamron – third party winner: Great Lens!
5c. ARSAT MC Yashma-4H (1990?):
I do not know much about this lens. Funny about it is to me, that in most cases, when it is offered as a used lens, it is given the addendum „sovjet lens„! In 1990, when it was delivered first (I saw other sources with the date 2007 …) the Sovjet Union no longer existed – which means that, ARSAT being located in KIEW, the lens has UKRAINIAN roots.
As far as I know, it was generally produced in Nikon-mount.
Open aperture and stopped down the lens is convincing in the center – about 10-15% below the other superteles – but with still very good CA in the center.
From f/4.0 it is also very good in the large part of the frame – just 10% below the Topcor.
In the corners it is on par with the Topcor open aperture – but it does not improve so much while stopping down. For analog film use it was also a good lens – with exception of the softer corners with typical CA-values of non-apochromatic lenses … and a much higher distortion than all the other superteles.
What about apochromatic correction in supertele-lenses?
Lenses of 300mm f/2.8 need apochromatic correction to be really sharp. The chromatic aberrations („secondary spectrum“) are the major restictions in sharpnes for these long focal lengths all over the frame! All these lenses, tested in this report, have apochromatic correction – in varying degrees of perfection! In the ARSAT Yashma the apo-correction is only partly successful.
fotosaurier, Berlin 13.02.2023
1- „Topcon Story – Topcon Enigma“ by Marco Antonetto and Claudio Russo, by Nassa Watch Gallery, Collectors Camera Publishing, CH 6907 Lugano, Switzerland – 1997
2- Web site „http://www.topgabacho.jp/Topconclub/FPslr1.htm“
This, the first super fast long telephoto lens produced for any camera system world wide, came to the market in 1957. This was a large and heavy lens, with a 130mm maximum diameter, a length of 412 mm and a weight of 3.3 kg. The optical design was one of 6 elements in 4 groups. The selling price, at the time, was 135,000 Yen making it the most expensive lens on the market. Special filters slide into a slot at the rear of the lens barrel and this lens was probably the first to use this method. Unlike the 135mm f2 R Topcor, this lens was listed in catalogues into the later half of the 1970s. Because of it’s large aperture it was chosen as the official lens of record for the Tokyo Olympics. An odd thing concerning this lens is that many of those remaining have been modified for the Nikon mount, while those with the original Topcon mount are very scarce. The early lens case was made of leather but later on Topcon began supplying a hard case with the TOPCON emblem promontory displayed. The R Topcor 300mm f2.8 lens still compares favorable, with regards to regards to sharpness and contrast, to modern lenses with fluorite elements. Today this lens is almost forgotten but was highly praised in former times.
3- Web site of Steven Gandy: „https://www.cameraquest.com/top30028.htm“