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Folded Newtonian Telescope
johanneswilm writes "Michael Fallwell has figured out a way to overcome many of the problems of traditional telescope construction - making it way more compact and economical. And the whole thing is completely portable and achieves accuracy down to one or two millionths of an inch across an 18 inch surface!"
True, but much of the point of the article is that it is within the reach of the extreme hobbiest to build a scope of this size.
And I know any number of hobbiests who spent far more on bicycle racing, or a kart, or golf, or their stamp collection, or modifying their car, etc. Fairly lower middle class income types among them.
Not to mention what the computer geeks/gamers I know have spent. The flight sim folks can get downright silly at times. God bless 'em; and I'd love a full motion cockpit myself.
Call it passionate hobbiest rather than extreme, and I'd say anybody setting out to grind their own mirrors rather than drive to the mall and pick up a Meade is, by definition, passionate about telescopes.
KFG
I have been an amatuer telescope nut (ATN)for quite a few years. Main reason to build a telescope yourself (other than the self satisfying geek factor) is that it is possible to build a very high quality scope (better than any consumer grade scope) for cheap.
It is quite within the range of any reasonbly competent person to grind and figuer a telescope mirror so that it is diffraction limited. This means that the surface has been shaped close enough to the ideal parabola (for a newtonian design) that the limiting factor for resolution is the wavelength of light you are interested in. In other words, the mirror is opticaly perfect.
The larger you go, the more difficult it is to do this, however.
unfortunatly, the design presented in the article seems to have been optimized solely for a lower eyepiece height, and all the rest of the choices made will result in a less than optimal image. eyepiece height.
the plate glass will make in very sensitive to temperature changes.
the large central obstruction will reduce contrast
the spray on mirror coating will almost certainly change the effective shape of the figure.
I could go on. There is not much to recommend this design other than eyepiece height.
But hey, the guy built his own telescope, and it works!