Systems in which the two astigmatic surfaces coincide are termed anastigmatic or stigmatic.
2.
Today's photographic lens state-of-the-art is apochromatic correction, which is, very roughly, twice as strict as anastigmatic.
3.
In the nineteenth century, opticians dug to the level of the Seidel aberrations, called mathematically the third-order aberrations, to reach basic anastigmatic correction.
4.
Schneider's inexpensive, classic Xenar asymmetrical, anastigmatic, 4-element, 3-group lens design was introduced in 1919, and is largely unchanged from the original Zeiss Tessar formula.
5.
The observatory dome houses a 50 cm anastigmatic Schmidt-V�is�l?camera, which was earlier located at Iso-Heikkil?Observatory, where it was used in an asteroid hunt to find 807 minor planets and 7 comets.
6.
It was charted by the Belgian Antarctic Expedition under Gerlache, 1897 99 . It was named by the UK Antarctic Place-Names Committee in 1960 for Emil von Hoegh ( 1865 1915 ), a German mathematical optician who designed the first double anastigmatic camera lens in 1893.
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