LARGE OBJECTS OF DESIRE
THE ZEISS ULTRAPHOT
"What is it?
Isn’t it HUGE!
Isn’t it BEAUTIFUL!
I want one!" *
During the early 1930s, it appears to have occurred to several European manufacturers that the time was ripe for the development of a ‘universal’ microscope that would incorporate its own camera and light source(s). Ideally, its design would provide for (almost) instant changeover from epi- to transmitted light illumination and even from photo-micrography to photomacrography, whilst the widest possible range of accessories would make the whole gamut of available microscopical techniques available ‘at the flick of the wrist’. All basic centration and other adjustments would be made at the factory and the developments in precision engineering would ensure that all the necessary attachments could be interchanged with very little further attention.
Something approaching this dream was first realised in the form of the Leitz Panphot, followed by the Zeiss Ultraphot and Vickers Projection Microscope. Most intriguing of all, and perhaps the least known, was the Zeiss 35mm. version designed by Kurt Michel in 1938.
The sales pitch for the ‘Universal Camera Microscope’ was: -
That some professional photomicrographers should have been less than enthusiastic about this development is hardly surprising: after all, their status was being threatened and there was an understandable hint of ‘we shall all be murdered in our beds’ in their published comments. Allen1 commented rather sourly that such instruments are intended for use "…. where the training of the operator might not be sufficiently broad to enable him to make his own adjustments" and there seems to have been a real fear that the Panphot, Ultraphot and their ilk would take all the mystery and skill (and knobs) out of photomicrography. Loveland 2, most of whose work seems to have been done with improvised apparatus which must have taken an age to set up, complained that "such a device lacks flexibility, for many decisions are made for the user".
More to the point, perhaps, was the criticism that even if it were true that camera microscopes could do the work of half a dozen dedicated instruments, it was also true that they could only be used in one mode and by one operator at a time. In the meantime, presumably, there could be another 5 microscopists forming an orderly queue while they awaited their turns. There was also the fact that some of the most radical changes of configuration were quite time-consuming and required great care since the fittings being exchanged were often heavy, fragile and costly to replace. In such cases it would probably be quicker and more convenient to use separate specialised instruments anyway.
The pre-war Panphots and Ultraphots were angular, ‘sit up and beg’ instruments that incorporated vertical bellows cameras but, while the former remained largely unchanged after WW2, the Zeiss microscope was completely re-designed by Michel, by then at Oberkochen, to become the Ultraphot ll. The rather startling new shape, like that of all his Standard series, was based on spheres and circles, heavily influenced by the famous model L stand of 1934. The real novelty lay, however, in the new (9 X 12 cm / 5 X 4 inch) camera which had a horizontal light-path, folded back on itself by two massive first-surface mirrors, and a vertical focusing screen situated just above the tubehead. The ‘bellows length’ could be varied by up to 30cm. by racking the two mirrors along internal rails, and an automatic exposure control system was provided, based on a vacuum photocell in the plane of the focusing screen. This, incidentally, was the first completely ‘automatic’ camera of any kind to be manufactured.
Although its tubelength was nominally 160mm., an optical trick was employed to produce a space in the Ultraphot’s tubehead in which the light was parallel, allowing analysers, compensators, Nomarski prisms, etc, to be inserted without upsetting the corrections of the objectives, as well as accommodating a complex magnification changer and focusing Bertrand lens. This involved the incorporation of a so-called ‘telan’ system (a reversed Galilean telescope) of which the negative front lens, except in the earliest models, is found in the nosepiece. A later modification of this arrangement allowed the development of a ‘widefield’ nosepiece that increased the diameter of the field of view by 25%.
The Ultraphot was originally intended solely as a large format camera microscope (the Photomicroscope was the concurrent Zeiss 35mm instrument), but changes in photomicrographic practice later led to the development of a (rather clumsy) 35mm photohead for it. This used a similar exposure control system to that of the Photomicroscope and boasted a clockwork motor-wind.
In spite of a number of (mostly small) modifications, the basic form of the instrument remained unaltered until its replacement, around 1973, by the monolithic and relatively commercially unsuccessful Axiomat. The most important change during its long lifetime appeared around 1970, when an entirely new automatic shutter mechanism, incorporating a photomultiplier, was fitted to both the 35mm and large format photoheads. A larger base had to be designed in order to accommodate the extra circuitry, and the ‘finish’ was changed to ‘two-tone’ grey from the black and ‘metallic’ grey typical of the majority of ll.s. This variant was called the Ultraphot lll. The only difference between this and the later lllB is that, in the latter, exposure control in the large format photohead is based on a light reading from the centre of the picture area, rather than just beyond its left hand side as in earlier models. Both lls and llls were marketed in ‘Met.’ and ‘Pol.’ versions but these designations merely indicated the accessories provided with them, the stands being standard issue.
As probably the most versatile microscopes ever made, the Ultraphots ll and lll could be fitted with a host of Zeiss accessories, including the 2 photoheads, 3 different nosepieces, 200-odd objectives, 8 stages, 11 vertical illuminators, at least 20 condensers, 9 light sources, and offered every known method of illumination and contrast enhancement technique. In addition, its design makes it almost ideally suited for the attachment of a wide range of shop-made gadgets. What would now be called the ‘build quality’ is quite extraordinary and, since such engineering never comes cheap (and there was an awful lot of it), they were really expensive. A 1966 Ultraphot ll with standard transmitted light equipment, ‘macro’ accessories and 2 photoheads cost £2,680, duty paid: the price, at that time, of a new detached bungalow in my hometown. Just the cost of the steel desk and power pack (almost £350) would have bought a terraced house with an outside loo and ample opportunity for modernisation.
Their imposing size (the desktop is 156cm. X 78cm, the microscope roughly 75cm. (h.) X 50cm. (w.) X 75cm. (d), mass 50 kg.+) no doubt contributed to their considerable value as status symbols in the 1960s and early ‘70s and, at a time when cost seems to have been a minor consideration, they came to grace the laboratories of the Great and the Good in surprising numbers. Now, at least 25 years on, they have been around longer than the majority of workers who use them and are widely regarded as dinosaurs with too many knobs. But ironically, as many university laboratory managers wistfully calculate how many PhD students could be fitted into the volume occupied by an Ultraphot desk, it is their size that has finally become their Achilles’ heel, and there are heart-rending accounts of their being heaved into skips at dead of night.
It is, of course, an ill wind....., and the decline in the fortunes of institutional Ultraphots has at last put these magnificent beasts within the reach of amateur microscopists who know a good thing when they see it and have the room. Actually, it is the massive desk that poses the greatest accommodation problem, and, in the case of a model ll this can be dispensed with completely in cases of absolute necessity. With the later models it will be necessary to find a convenient place to park the largish drawer containing the power pack. Note, however, that if the desk is not used, a bench with a top at least 760mm (30 inches) deep must be provided.
An Ultraphot ll stand with binocular tube, rotating mechanical stage, 5 x 4 photohead and two lamphouses, in very good condition, now has a market value of little more than seven hundred and fifty pounds and a fair selection of accessories are relatively easy to come by. On the other hand, the acquisition of something particularly exotic in the way of attachments: a 4-axis universal stage or a Lebedeff polarising interference contrast outfit, for instance, may require considerable patience (and luck). Optical components are not cheap (and therefore make excellent presents), though, to take an extreme case, it would be unreasonable to expect a 63 / N.A. 1.4 planapochromat (last ‘new’ price: well over £3000) for the cost of a good dinner.
Routine servicing is simple enough, and information, advice, encouragement, counselling, and (sometimes spares and accessories) are readily available here or from members of the users’ network.
*(or two). First steps toward Ultraphot Mania.
© Spike Walker 1998