John Wall (inventor)

John Wall
John Wall
Born	1932 Crayford, Kent, England)
Engineering career
Significant design	Crayford focuser
Significant advance	dialyte based refracting telescopes

John Wall (born 1932 in Crayford, Kent) is an English design engineer, amateur astronomer, amateur telescope maker and member of the British Astronomical Association, now living Coventry England.

John Wall's aptitude for engineering won him an apprenticeship with Vickers Armstrong 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. He went on to become a design engineer at Vickers and, while working there in 1969, came up with the idea for an accurate mechanically simple eyepiece mount for amateur telescopes, the Crayford focuser. He is also known for designing dialyte based refracting telescopes, coming up with the Zerochromat retrofocally corrected refractor, including a folded 30-inch f/12 version he built in 1999.

Drawings for the Crayford focuser

30-inch dialyte refracting telescope

...
Wikipedia