18 inch F/4 Ultralight Parabolic Dobsonian Telescope Mirror For Sale
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18 inch F/4 Ultralight Parabolic Dobsonian Telescope Mirror:
$1950.00
Brand new just figured ultralight Newtonian Dobsonian mirror by PrecisionPro Optics. This mirror is only 0.82 inch thick and weighs an incredibly light 16 lbs! The lightest mirror possible for this aperture and performance.
It can be used to construct a hyper-portable scope, with the fastest cool-down/thermal equilibration time achievable.
Focal length is 71 inches and at least 1/4 wave P-V wavefront, provided a proper 18-point flotation mirror cell is used. The star test shows essentially perfect spherical correction, better than 1/10 wave.
The Foucaultgram shows a smooth, well corrected figure. The green LED illuminated surface. (The grey reflections are of some background objects, not on the mirror itself).
The mirror can be supplied with a chemically deposited silver coating for a $50 extra charge. Alternatively, the mirror can be sent to a vacuum deposition aluminum coater of your choice and expense. (Note: The silver coating performs similar to aluminum coatings with a slight reflective advantage in the red, but is not as durable as aluminized coatings, requiring more careful protection, and would need more frequent recoating under typical usage conditions.)
Free shipping to one USA destination. International shipping and customs charges are responsibility of the buyer.
