Takahashi Seisakusho

Takahashi Seisakusho Ltd. (株式会社高橋製作所) is a Japanese manufacturer of telescopes and related equipment (such as eyepieces and equatorial mounts) founded in 1932 by Kitaro Takahashi in Tokyo.

Originally started as a foundry, Takahashi began manufacturing optical equipment after WWII in 1946.

[1] Often known simply as 'Tak', the brand is especially noted amongst amateur astronomers for its range of apochromatic refractors, but also produces various types of reflectors, and instruments featuring compound optics.

[2] Takahashi pioneered the use of fluorite crystal in place of one of the glass elements in the objective lens of an astronomical telescope, although this material had previously been used in other optical devices.

In recent years however, Takahashi has produced some telescopes using extra-low dispersion ("ED") FPL-53 glass[4] in place of fluorite in the objective lens.