English Cameras & their Lenses

Jethro, Going Postal

If you ask many people, who, they think, were the most innovative, ‘cutting-edge’ in cameras and lenses, the answer would probably be either, ‘The Germans’ or, possibly, ‘The Japanese’; ask them who made the lenses for Hollywood in the 1920’s, and they’d probably venture ‘The Americans…?’

What about this Country…? ‘Nothing much, a few bottom-of-the-range cameras, with indifferent-to-poor lenses to match…We could never approach – let alone beat – the Germans for lenses…’ And the best camera in the World? ‘Leica.’ Everybody knows the brand name, even if they’ve never heard of Oskar Barnack (who made them), at Ernst Leitz’s works in Wetzlar (LE-itz + CA-mera = Leica, in a typically 1925, ‘art-deco’ kind of way, but with more inherent meaning than the brand-name chosen by George Eastman, which, if anything, represented the sound made by the shutters of his cameras: Kodak – think of a really old box-camera, and the simple shutter made a sound plausibly like K…DAK). Here, incidentally, from the Leica site, is Barnack’s 1913 picture, taken with his fledgling camera:

Jethro, Going Postal

He had, I imagine, to prove that his silly notion of taking a picture on a tiny piece of cine film (smaller even than the smallest ‘tin-type’ – 1/2” x 1”), instead of on a decent-sized glass plate – 8 1/2” by 6 1/2” for ‘Whole-plate’ –  might actually work. Then there was a four-year gap, brought about by the Prussian Generals and Admirals – with an unstable figurehead Kaiser to blame, and then several years before a fragile kind of normality returned…

So, what was the lens this great German camera-maker put on his revolutionary camera? Barnack tried several lenses, but found them unsuitable, mostly because they were designed for the different format used in ciné, rejecting not only Leitz’s own Mikro-summitar but Zeiss’s Tessar (designed much earlier by Rudolph and still known and respected), in favour of, and here the Leica site waxes somewhat coy, ‘a 50 mm f/3.5 design based on the Cooke triplet of 1893’. Cooke? Not a very German name, Cooke!  “Sure you don’t mean ‘Kuch’, or ‘Koch’, Fawlty? Most of those Germans have pretty German-sounding names, y’know – like Francke und Heidecke, Guthe und Thorsch, Goltz und Breutmann, Braun, and Ernemann, and Goerz. Don’t care for Germans, Fawlty!” (apols. to  ‘Major Gowen’ – Ballard Berkeley). ‘ Based on’: that wouldn’t be a way of getting around any patents would it? There are those who reckon that Zeiss’s famous Tessar was itself a derivative from Cooke’s Triplet…perhaps just a way of putting off the evil hour of having to mention a non-German.

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Opticians had long observed that a single piece of glass, ground to a curve – whether both sides curved, one side flat (‘plano-convex’), or one side incurved (‘meniscus’) – made an image with a number of distinct imperfections (‘aberrations’), the most immediately noticeable one being a rainbow effect – particularly at the edges (if you have cheap Binoculars, you’ll know about this); thus, the first goal of lens-makers was the elimination of this ‘chromatic aberration’. ‘Glass is glass’ you say, even while paying over the odds for a vase, decanter; or bowl because it says ‘75% lead Crystal’ on the label. Someone more knowledgeable than you had exploited those very characteristics, to give you glass that was not just heavy, but where the sharp edges where it was cut, produced brilliant, flashing rainbows: ‘Crown’ for windows, ‘Flint’ for glassware, and, with an addition of Lead Oxide, ‘Crystal’. ‘Crown’ glass and ‘Flint’ glass were the two known types of optical glass, and John Dolland patented the already-known ‘achromatic’ lens in the 1750’s, having written papers for The Royal Society on the subject, and been awarded The Copley Medal in 1758.

Jethro, Going PostalThe next stage in lens-development, was a back-to-back version of the Doublet, but using cemented menisci, and was patented by John Dallmeyer in 1866 who had come to England 11 years earlier, working for the great English Optician Ross, marrying into the family, and inheriting one third of the estate. I often wonder whether part of the reason English people so highly rate Dallmeyer lenses, might be because, well, he sounds pretty German.

Jethro, Going PostalFor some while, Dallmeyer had to dispute his title to this design with Carl Steinheil. Jethro, Going Postalthe attractive philosophy behind this development lay in the idea that the symmetrical nature of the design could only improve things (rather like ‘push-pull’ in amplifiers – or ‘negative feedback): as it did – verticals at the edges being rendered straight (notice Barnack’s 1913 picture, like so many early street-views, is taken where angles can hide the unstraightness at the edges), not bulging (‘barrel distortion’), and with commendable sharpness – but with a maximum aperture of f8, whereas the old Petzval lenses (Joseph Petzval was suitably foreign, Hungarian)– ideal for their flattering softness in Portraiture – had been considerably ‘faster’, about f2.9, enabling portraits to be taken before the subject moved.

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So, ‘two elements good, four elements better…’, and lenses of increasing complexity were made, throwing up more problems: every piece of glass not only refracts light but reflects it, and the greater the number of bits of glass, the more multifarious the reflections: while the designer aimed at eliminating, or at least minimising, as many aberrations as he could, the more glass elements there were, the more ‘flare’ and ‘ghost images’ were introduced, reducing contrast and muddying the image. Because of the curvature of a lens, the image itself was difficult to keep flat, some camera-designers actually curving the film-plane to accommodate this: not something easily achieved with glass plates! Before long, lenses of ten elements were being designed and made, although Goerz’a ‘Double Anastigmat’ (the ‘Dagor’- DOppel, Anastigmat, GOeRrz…) of six elements became the ultimate in desirability for many photographers for decades.

In the midst of all this manic, Galvanic excitement, a little-noticed and now hardly-remembered York lens-maker/engineer, finding his own firm (‘Cooke’) was not interested in his lens (they couldn’t be: their business was Telescopes, and they’d over-committed themselves with one particular project), took his design to a Leicester firm, Taylor, Taylor, & Hobson, who went on to make it: ‘The Cooke triplet is a photographic lens designed and patented (patent number GB 22,607) in 1893 by Dennis Taylor who was employed as chief engineer by T. Cooke & Sons of York. It was the first lens system that allowed elimination of most of the optical distortion or aberration at the outer edge of lenses’

[Wiki] Wiki, having described Cooke’s Chief Optical Designer as an engineer, goes on to explain some of its elegant simplicity: ‘A Cooke triplet comprises a negative flint glass element in the centre with a crown glass element on each side. Jethro, Going PostalIn this design, the sum of all the curvatures times indices of refraction can be zero, so that the field of focus is flat (zero Petzval field curvature). In other words, the negative lens can be as strong as the outer two combined, when one measures in dioptres, yet the lens will converge light, because the rays strike the middle element close to the optic axis. The curvature of field is determined by the sum of the dioptres, but the focal length is not.’   Here is the caption to Wiki’s diagram of H.Dennis Taylor’s ‘Cooke Triplet’: ‘Introduced in 1893; Author Dennis Taylor; Construction 3 elements in 3 groups’ Aperture f3.5’(Cooke’s Telescope business went on to become part of ‘Cooke, Troughton, & Simms’ in 1922, and later, having produced a lot of gunsights etcetera in WWII, became part of the Vickers group). Given the Imperial German pretensions to Supremacy, I can quite imagine that, even twenty years after Mr. Taylor’s landmark achievement, it would stick in the craw of a German Camera firm to cede any appearance of taking advantage of an English invention…and with its Patent with still a few years to run.

As just a couple of examples of what seem to be ‘Englishness’, H.D. Taylor’s way of designing lenses used algebraic formulae – up to a point: and then went to ‘trial-and-error’ ‘tinkering’ (the more thorough German approach seems to have been design using the Formulae and Data-tables, and only descend to ‘bench-tests’ as a last resort; the English approach allows for serendipity and inspiration, the dogged German one might gain by its ruthless thoroughness, but perhaps loses through its lack of a Puck-like quality. The second example of ‘Englishness’ is evident to me in the entirely honourable way in which ‘TTH’ – for whom ‘The Cooke Triplet’ must have come as an uncovenanted benefit, did both H.D. Taylor (no relation) and the York firm for whom he worked, the decent thing of acknowledging both on every such lens they made: would any American firm have been so generous – I am thinking how the only publicity Wurlitzer gave Hope-Jones, was of the negative variety.

Jethro, Going Postal

Another example of the benefit of this lateral-thinking approach: “Around 1896 H. Dennis Taylor observed that some old lenses that had become tarnished by exposure to the atmosphere actually transmitted more light than a newly polished lens…” [Kingslake, History, p.16]. In 1904, H.D. Taylor patented the use of chemicals to induce similar ‘blooming’ on lenses, something that ‘got into its stride’ around the end of WWII, in a different form: by deposition of a film of Magnesium Fluoride under vacuum.

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In answer to the almost Rhetorical Question posed at the start, those Hollywood camera lenses were made by…[drum roll… GONG]

“Taylor Hobson supplied over 80% of the world’s lenses for film studios.” [Wiki on TTH’s history], Hobson being the Rolls, as it were, although the Engineers Royce were less astute in allowing their salesman to put his name first, the two Taylors – who’d set up in 1886 – making sure they, Optician and Engineer, came first.

Some Quiz-type questions, to get you racking you brains and ransacking ‘t’interweb-thingy’:

What have WWII Bombers to do with all this?

What has Desperate Dan’s Aunt got to do with it – or a company known for ok-ish loudspeakers?

“Lo, thou trustest in the staff of this broken reed, on Egypt; whereon if a man lean, it will go into his hand, and pierce it” – so, best to keep well away from even a broken Reid?

Which would be better: a poor Witness, or a good Advocate?

Well, you know I go in for a bit of flag-waving, but which particular flag has any connection with this topic (and, should you have a tropical one, should you wave it fire it… or do something else?

Jethro, Going Postal
A  Cooke Triplet‘tribute’ picture from the ‘MF Forum thread on Triplet lenses

[Apart from the inevitable ‘Wiki’, sources consulted include: ‘The Lens Vademecum’, M. Wilkinson 2nd. Ed. on CD-ROM; ‘The Ilford Manual of photography’, 1958 – which first sparked my fascination with lenses in about the same year; ‘Photographic Optics’, A. Cox, 15th. Edn, 1974; A History of the Photographic Lens, R. Kingslake, 1989]
 

© Jethro 2018
 

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