John Wall is a British

British people

The British are citizens of the United Kingdom, of the Isle of Man, any of the Channel Islands, or of any of the British overseas territories, and their descendants...

 design engineer, amateur astronomer, amateur telescope maker

Amateur telescope making

Amateur telescope making is the activity of building telescopes as a hobby, as opposed to being a paid professional. Amateur telescope makers build their instruments for personal enjoyment of a technical challenge, as a way to obtain an inexpensive or personally customized telescope, or as a...

 and member of the British Astronomical Association

British Astronomical Association

The British Astronomical Association is the senior national association of amateur astronomers in the UK.-Function:It encourages observational astronomy by non-professionals in areas which cannot be covered by professional observatories...

, now living Coventry

Coventry

Coventry is a city and metropolitan borough in the county of West Midlands in England. Coventry is the 9th largest city in England and the 11th largest in the United Kingdom. It is also the second largest city in the English Midlands, after Birmingham, with a population of 300,848, although...

 England.

Biography

John Wall aptitude for engineering won him an apprenticeship with Vickers Armstrong

Vickers Armstrong

Vickers-Armstrongs Limited was a British engineering conglomerate formed by the merger of the assets of Vickers Limited and Sir W G Armstrong Whitworth & Company in 1927...

 at the age of sixteen in the town of Crayford where he was born. He served in the army with the Royal Electrical and Mechanical Engineers in early 1950s and there became interested in telescopes and astronomy

Astronomy

Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...

. He went on to became a design engineer at Vickers

Vickers

Vickers was a famous name in British engineering that existed through many companies from 1828 until 1999.-Early history:Vickers was formed in Sheffield as a steel foundry by the miller Edward Vickers and his father-in-law George Naylor in 1828. Naylor was a partner in the foundry Naylor &...

 and, while working there in 1969, came up with the idea for an accurate mechanically simple eyepiece

Eyepiece

An eyepiece, or ocular lens, is a type of lens that is attached to a variety of optical devices such as telescopes and microscopes. It is so named because it is usually the lens that is closest to the eye when someone looks through the device. The objective lens or mirror collects light and brings...

 mount for amateur telescopes, the Crayford focuser

Crayford focuser

The Crayford focuser is a simplified focusing mechanism for amateur astronomical telescopes. The design replaces the complicated rack and pinion drive normally found in this type of device with a smooth spring-loaded shaft which holds the focus tube against four opposing bearing surfaces...

. He is also known for designing dialyte based refracting telescope

Refracting telescope

A refracting or refractor telescope is a type of optical telescope that uses a lens as its objective to form an image . The refracting telescope design was originally used in spy glasses and astronomical telescopes but is also used for long focus camera lenses...

s, coming up with the Zerochromat retrofocally corrected refractor, including a folded 30-inch f/12 version he built in 1999.

External links

• A New Refractor Concept: "The Wall Hypochromatic Refractor"
• The John Wall 30-inch refractor.
• The Crayford eyepiece mounting by John Wall - Journal of the British Astronomical Association, 81 (2), 118, February 1971
• Crayford focusers
• Crayford Eyepiece Mount
• astronomics.com's description of how the Crayford Focuser works
• Toshimi Taki's description of how to build a cheap Crayford Focuser