Talk:Segmented mirror

Please explain how the segmented mirror works

It would be valuable if the article explained how smooth images of distant targets can be collected using a large mirror composed of separate segments which are separated from each other by obvious borders, edges, and angles between them.

The creation of lenses and mirrors for optical instruments typically involves grinding and polishing the optics as smoothly as possible, to high degrees of perfection, and the creation of very precise and even curves. Segmented mirrors are a deviation from this traditional masterful approach since the component segments break the tradition of smoothness and continuous curvature.

How can unbroken views of high optical quality be achieved using bits of mirror stuck together with so many facets, like a mosaic? Is software used to interpolate broken data across the seams, for example, or does the light work with the reflecting facets in some way that forgives the imperfection of the reflecting surface? --O'Dea (talk) 19:39, 22 July 2010 (UTC)

Its a good place for expansion. "smoothness and continuous curvature" is the reason why they build segmented mirrors. Each small segment can hold an exact shape and all segments can be aligned by active computer control. As for the effects of so many facets, part of this is already covered in Reflecting telescope. All Reflecting telescopes have the image broken up into "facets" because they all have some obstruction blocking the primary mirror causing diffraction effects. These "imperfections" do not break up the image because all surfaces reflect to a common point. But they do reduce contrast and cause diffraction effects. There is a good ref at Optics in astrophysics By Renaud Foy, Françoise-Claude Foy. Fountains of Bryn Mawr (talk) 02:34, 31 July 2010 (UTC)

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The "concept" of segmented mirror telescopes is older than Jerry Nelson

In fact a working 180 cm mirror, made of 61 hexagonal segments, was completed in 1952 by Guido Horn D'Arturo, after building a prototype in 1939. The article on the Italian WP has plenty of material and sources on this subject. This should be reflected in the opening of this article.

The 1952 mirror.

--79.55.19.202 (talk) 00:35, 29 December 2021 (UTC)