WebbAstronomers have usually employed a Hindle sphere to test the secondaries of Cassegrain and Ritchey-Chretien telescopes. For very large telescopes, such as the 7.6-m telescope planned by the University of Texas, the cost of a traditional Hindle sphere (approximately 200 in. in diameter) is high enough to justify a search for a less … Webb31 jan. 2024 · The Hindle sphere had a diameter, clear aperture, and RoC of 154, 140, and 450 mm, respectively. The tilt errors of the convex were chosen as 0.0010°, …
Schematic optical diagram of the telescope. - ResearchGate
WebbFor high-aperture hyperbolic surface, we use two Hindle spheres to test one mirror. At the present time, we have developed the test procedures for high-aperture surfaces of primary (diameter 4100 mm, asphericity about 881 m) and secondary (diameter 1240 mm, asphericity about 364 m) mirrors for the VISTA Project as well as the Fizeau test set-up … Webb1 juli 2013 · However, ASI(Q) measures optics that are smaller than 550 mm in diameter, also, it is expensive. Yan adopted the Hindle test for the subaperture stitching method and used a small Hindle sphere [15 ... braintree high boys basketball
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WebbClearly, Hindle test is limited to surfaces with usable far focus, which eliminates sphere (ε =0, near and far focus coinciding), prolate ellipsoids (1> ε >0, near and far foci on the same, concave side of the surface), paraboloid (ε =1, far focus at infinity) and hyperboloids close enough to a paraboloid to result in an impractically distant far focus. Webb20 jan. 2011 · Setting up to do the hindle test is surprisingly easy. If your primary is f/4 then an f/2 sphere can be half the size. And I see chipped c8's c11's and even c14 primary mirrors here for sale all the time, for dirt cheap. To use the hindle sphere all you need to know is P and P' and the radius of the sphere. WebbIt describes a method of testing a convex mirror with an auxiliary Hindle sphere and of optimizing this method by using two Hindle spheres of smaller diameter for one item … hadleigh woods adult community windham nh