Newtonian telescope secondary mirror. This design reduces the size and cost of the telescope with a shorter overall telescope tube length (with the corrector extending the focal length in a "telephoto" type layout) combined with a less costly spherical mirror. Commercially produced versions of this design have been noted to be optically compromised due to the difficulty of producing a correctly shaped sub-aperture corrector in a telescope targeted at the inexpensive end of the telescope market. Newtonian telescope The Newtonian telescope, also called the Newtonian reflector or just the Newtonian, is a type of reflecting telescope invented by the English scientist Sir
Hermanos Conde themselves ""Sobrinos de Domingo Esteso Conde Hermanos"" (Esteso's Nephews, Conde Brothers) or ""Hermanos Conde Sobrinos de Domingo Esteso"" (Conde Brothers, Esteso's Nephews). Mariano Sr. later established his own shop close to the Royal Theatre, calling it "Conde Hermanos Sucesores Sobrinos de Esteso". His two sons, Felipe, born in 1957 and Mariano Jr., born 1959, began their apprenticeship with their father and uncle Faustino when they were about 15 years old. Faustino died in 1988 and Mariano Sr. in 1989. Felipe and Mariano Conde (sons of Mariano Conde Sr.) manufactured flamenco guitars in their workshop at Felipe V St. nº 2