Polarising eyepiece for solar observations.

Made by Carl Zeiss in Jena, Germany, 1890-1920.

Telescope eyepieces vary widely in size, focal length, and design. This polarising eyepiece was used with Sydney Observatory’s 11.4 inch telescope (H9886) to make solar observations.

The 11.4 inch telescope was purchased in 1874 by Government Astronomer H. C. Russell for the upcoming Transit of Venus. The telescope had a clear aperture of 11.4-inches and a focal length 12 feet 6 inches and Russell commented that while this shortened focal length was a disadvantage to definition it was an advant...

Summary

H10026
A polarising eyepiece used for solar observations. The eyepiece consists of two metal cylinders with enclosed ends one on top of the other. The upper cylinder is smaller in diameter than the lower cylinder. The upper cylinder rotates on the lower cylinder and there is an engraved scale on the surface of the lower cylinder. There is a cylindrical brass screw fitting fixed on either side of the eye piece to allow it to be attached to a telescope.

Observatory stock number 105.

Dimensions

120 mm

Production

The eyepiece was made by Carl Zeiss in Jena, Germany between 1890 and 1920.

In 1846 Carl Zeiss (1816-1888) started his instrument making business in a small town of Jena in Germany. He quickly became interested in optics and by 1848 was making and designing microscopes. By 1866 Zeiss realised that to expand his business he needed someone with a greater understanding of optics. Zeiss found the right person in Ernst Abbe (1840-1905) and by 1870 they had devised a new way for computing the manufacture of optical lenses which would improve performance by eradicating much of the colour and spherical distortion of the lens.

In 1879 they produced the homogenous immersion objective but the flint and crown glass which they used to make their lenses needed to be improved before they could perfect their lenses. Optical glass made from silica, soda and potash was supplied by manufacturers who used the same recipes for much of the nineteenth century. It was only after Zeiss and Abbe teamed up with the glass maker Otto Schott in 1881 that they were able to produce a better quality glass without so much of the characteristic green or yellow tinges.

In 1886 Zeiss and Abbe produced the apochromatic (better colour correction than an achromatic) microscope lens. Consisting of ten lenses it effectively removed secondary spectra distortion and spherical aberration. Using the new glass and Abbe's formulas the Zeiss factory began producing their famed anastigmatic photography lenses in 1890. It was around this time that the Zeiss works began constructing eye pieces and objectives for telescopes.

References
Auerbach, F., The Zeiss Works and the Carl Zeiss Foundation in Jena, W. & G., Foyle, London, England, about 1925?

Written by Geoff Barker,
Assistant Curator, November 2007.
Carl Zeiss 1890-1920

Source

Source unknown
14 November, 1983

Cite this Object

Polarising eyepiece for solar observations. 2016, Museum of Applied Arts & Sciences, accessed 28 June 2017, <https://ma.as/230592>
{{cite web |url=https://ma.as/230592 |title=Polarising eyepiece for solar observations. |author=Museum of Applied Arts & Sciences |access-date=28 June 2017 |publisher=Museum of Applied Arts & Sciences, Australia}}
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