You will usually find lenses from Aldis designed for aerial photography, enlarging, projecting or copying purposes. However, slide projectors, WWI rifle scopes, periscopes or binoculars also came off from the production line. But the real breakthrough was made by Arthur Cyril Webb with the signal lamp. However, the close ties to the military carried a downside in the production outage of photographic equipment - the motherland took precedence.

• The signal lamp is used for long-distance communication via Morse code flashes. The Aldis ones went through both wars, but in 1944 the younger brother came up with such an improved design that they were even given the general name of Aldis lamp. It came in handy on the ground in the trenches, on vessels on the water, and between aircraft in the air. I'm afraid I haven't been able to find out whether anyone took it into space aswell.

• Enlarging lenses are used - beware - in enlargers. With these, one enlarges (sic!) the negatives on photosensitive paper in a darkroom and positively develops them. Yes, it's still being used, and yes, we know there are printers. However, even the best printer cannot battle the good old fibre-based paper.

• Copying, or reproduction, or process lenses were used for duplicating various documents, scientific work etc. You can find out how they differ from normal photo lenses here. You can read something about aerial photography from my article here.

• Projection lenses are - oh yeah - in projectors. Whether those for filmstrips or slide projectors. I won't put links here anymore, or Wikipedia will think someone is DDoSing it.

• The marking and use of the UNO design by this company is very inconsistent and confusing - sometimes the barell is marked, sometimes not. In later years, the company also switched to conventional three or four elements designs without visually marking the changes. Thus, without disassembling the lens, you can rarely be sure (unless UNO is marked on the lens body).

• The UNO and its successors (TRIO) also functioned as casket sets, whereby adding, removing, or swapping elements and secondary lenses changed the focal lenght, hence the aperture and scheme. They were thus a kind of primitive predecessor of today's zoom lenses. Complete sets, however, have rarely survived into modern times in general - in this case, it's a Sisyphus-like effort in search of them.

• Arguably the rarest item in the portfolio is a series marked Series 0. These were portrait anastigmats with f3 aperture and a separate ring with adjustable soft-focus effect. A true blue blood testifying to a skill that few have achieved.

The output (for chart lovers it is a later revision of the Series III No.10, 16.25in f7.7) is just sharp enough with very nice contrast and enough coverage for the 8x10" format (when fully open it will cover 10x12" at infinity, so it has plenty of movement on the smaller formats). The lens is also, like the triplets, very amenable to "fake" soft-focus, which can be adjusted by screwing the front - the result is pleasing and not unlike much more expensive specimens designed for this purpose. Its pleasant weight and small dimensions thus predestine it for universal use under almost any conditions and requirements. And thanks to the unusual dark bronze-gold lacquer on the brass body, it's also nice to look at.

Over the years I have only come across two examples - both in my hands - and both with experiences from the Indian subcontinent. The first served for many years under the British colonialists in a studio in Bombay and then in Kerala, where it also remained after 1947 and independence from the British Empire - before coming to me in Prague. The second found a home in Pakistan, as evidenced by the signing on the body - "Shanco The Mall Lahore." The meaning of the first words remains unclear; but Lahore is the largest city in the country. Pakistan separated from India in the same year as the collapse of the British Raj, but unlike the first case, this piece has returned to its motherland... before he came to see me in Prague.

The presence of imperial technology in the territory of the Dominion is not surprising, yet the level of Aldis presence in this particular part of the Commonwealth surprised me and I searched for the reasons. In the dusty shelves of British university libraries I eventually found a plausible cause - the family had lived here for some time and Lancelot was born in Calcutta in 1870 before being sent back to England at the age of five. He seems not to have forgotten his native land and he kept it well supplied with his factory toys. Thanks for that, almost-knight Lancelot - I immediately look at your lenses differently, wondering what exotic adventures they must have had and will no longer tell.