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 Hermanos Conde Hermanos Conde (Conde Brothers) are luthiers, makers of classical and flamenco guitars. The Conde dynasty was founded in Madrid by Domingo Esteso in 1915. Esteso trained his nephews Faustino and Mariano Conde Sr. Later, the young Julio Conde joined his brothers. Domingo Esteso died in 1937, and after that time the three Conde Brothers continued working for Esteso's widow under the name of "Viuda y Sobrinos de Esteso" (Esteso's Widow and Nephews) until 1960. In the early 1950s, Julio Conde set up a new handicraft guitar center. From 1960 until 1988-89 they took over the shop and called