Quote:
Originally Posted by Bill Cooper
No one I have talked to has be able to spot a flaw in the optics of this system.
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Don't bother, it won't work for several reasons and the originator is so hopelessly ignorant of basic optics that I am lost as to where to start. It's on par with the mathematically illiterate trying to disprove Einsteins theory of relativity.
Cylindrical trough mirrors have their uses though, as solar collectors and for some radar applications where the beam is essentially swept over a plane. As Bojan points out they're also used in spectroscopy and in some scanning applications where there is a linear element in the path - either a grating (a bunch of lines), a prism, a narrow slit, or a linear CCD detector.
But what that article proposes is really really flawed in so many ways.
Firstly, he doesn't understand that a parabolic cylindrical mirror produces a line focus (not a point) from a distant point object (star or the sun). If you use two cylindrical mirrors with the axes at 90 degrees, what you will get is two lines crossed, not a point.
In each plane, what he shows is one-half of a cassegrain two mirror telescope. What he shows is afocal - no image plane and the rays are parallel, not converging to form an image. So IMHO he doesn't even understand how an image is formed.
He's also ignorant of the geometry concerning the angular magnification in a two-mirror telescope, and that by displacing the mirrors along the optical axis, while it may produce the same magnification in the vertical and horizontal planes, the angular magnifications will be different and there is not the slightest chance of this producing a coherent image.
I'll give you an easy analogy that most might understand. Buy two 8" Maksutov cassegrains from Intes Micro, one being an f/10. the other being f/12. Using a diamond saw, cut both in half along the optical axis.
Now glue the left half of the f/10 scope to the right half of the f/12 scope. Good luck trying to combine the beams into an image !
