His Wave Theory of Aberrations, (published by Oxford University Press 1950), is central to all modern optical design and provides the mathematical analysis which enables the use of computers to create the highest quality lenses.

Due to his own genius and the good fortune of having the support of both his family and teachers, he obtained one of only two scholarships, in the whole of Leicestershire, enabling him to attend The Gateway Grammar School.

(He was a natural, quickly rising to the rank of 'acting unpaid lance corporal' and winning a prize for his speed at dismantling and reassembling his rifle.)

In addition to his own work, he attracted a large number of high quality PhD students from all over the world, many of whom became senior academics and researchers themselves.

The development of the mathematical description of the behaviour of optical systems was at the centre of his life's work in physics – the application of which produced many world-famous inventions.

He chose to remain at Reading in the post of Professor of Applied Physical Optics until his retirement in 1984, declining the numerous top appointments he was offered.

[5] The accompanying Lister Oration, given at the Royal College of Surgeons of England, was delivered on 11 April 1991, and was titled 'The development of the modern endoscopes – present and future prospects'.

What is less well-known about Harold Hopkins is that he was also a politically committed man of the left, being an early member of the Communist Party of Great Britain.

Coming from a poor and under-privileged background, he understood how essential equal opportunities and good education were if ordinary working class youngsters like himself were to prosper in society.

Although there had been earlier attempts to produce a lens which could achieve continuously varying magnification without re-focusing, none of them could provide a good quality image throughout their zooming and aperture ranges.

Then, when sufficient turns had been added, a short section could be sealed in resin, cut through and the whole straightened out to produce the required coherent bundle.

At the same time a Dutchman, Abraham van Heel was also trying to produce coherent bundles and had been researching the idea of cladding each fibre to reduce this 'cross-talk'.

Eventually a system for cladding fibres with a layer of glass of lower refractive index was developed by Larry Curtis et al., which reduced the leakage to such an extent that the full potential of the fiberscope was realised.

Other innovations included the use of additional fibres to channel light to the objective end from a powerful external source (typically a xenon arc lamp) thereby achieving the high level of full spectrum illumination needed for detailed viewing and good quality colour photography.

In the medical application, alongside the improvement to the optics, came the ability to 'steer' the tip via controls in the endoscopist's hands and innovations in remotely operated surgical instruments contained within the body of the endoscope itself.

With the appropriate curvature and coatings to the rod ends and optimal choices of glass-types, all calculated and specified by Hopkins, the image quality was transformed – light levels were increased by as much as eightyfold with no heat; resolution of fine detail was finally achieved; colours became true; and diameters as small as a few millimetres were possible.

Seeing promise in this system, Karl Storz GmbH bought the patent and in 1967 began to produce endoscopic instruments with a tremendously brilliant image and superb illumination.

It is calculated from the lens data using software such as OSLO, Zemax and Code V. Originally an analogue video play-back system, the Philips laserdisc format was adapted to digital in the late 1970s and was the forerunner of the CD and DVD.

Hopkins was able to show by a thorough mathematical analysis of the system, that with a carefully calculated geometry, it was possible to use a single piece of transparent moulded-plastic instead.

Whilst not directly involved in the applications of optics, this new facility, in its pursuance of the highest standards of teaching and research, provided an opportunity to honour one of the University's most illustrious academics.