Weltevreden SA
04-03-2013, 12:13 AM
Three-dimensional (3-D) solid object printing is presently in its youth stage: showy, object-centred, and expensive. In time the technology will mature into consumer-aware innovation and affordability. This is a good time for we astro buffs to dream up the equipment that at present we can only dream about. Take eyepieces: bonding materials with different refractive dispersions directly to each other without cements or air can inspire a host of improvements, in the same way 3-element cemented ultrascopic eyepieces reduce lateral color and astigmatism in ways air/cement-spaced orthos do not. And who hasn't looked into the front of an oil-spaced apo to marvel at the nothing which reflects back? Similarly, generating an entire eyepiece in one go (or rather flow) eliminates retaining ring problems and the internal fogging that nitrogen and argon are intended to purge.
That's eyepieces. The prospect of single-element objectives with four or six internally aspherised surfaces and no contrast loss at every surface interface is (almost) enough for me to hold off purchasing the Next & Best scope that's always being touted on some forum or other—to say nothing of a ready response to the Household Budget Director who pounces on every dream scope discussion at the dinner table to remind me that the contents of female closets quickly go out of date, too.
Lots of issues come up. Would optical surfaces layered directly on each other at the molecular level need the 1/4- or 1/8-lambda surface precision of air or bonded glass? Reducing high-lambda polishing to field and eye surfaces would be a cost-cutter right there, but do the plastics that would necessarily be used for 3-D optics have the internal homogeneity that high-contrast viewing requires? Can electronic circuits be molded into their housings in a way that minimizes those cranky hand paddles and their moisture-sensitive connections to the RA and dec drives?
If we think through the improvements we want ahead of the manufacturers—maybe with a dose of optical math and design sketches thrown in—we, not they, would have the upper hand in product intros. Yes, all this is way ahead of the 3-D printing affordability curve at the moment. But isn't this the best time to dream up all the good-better-bests we can and let the manufacturing community know how many of us there are?
That's eyepieces. The prospect of single-element objectives with four or six internally aspherised surfaces and no contrast loss at every surface interface is (almost) enough for me to hold off purchasing the Next & Best scope that's always being touted on some forum or other—to say nothing of a ready response to the Household Budget Director who pounces on every dream scope discussion at the dinner table to remind me that the contents of female closets quickly go out of date, too.
Lots of issues come up. Would optical surfaces layered directly on each other at the molecular level need the 1/4- or 1/8-lambda surface precision of air or bonded glass? Reducing high-lambda polishing to field and eye surfaces would be a cost-cutter right there, but do the plastics that would necessarily be used for 3-D optics have the internal homogeneity that high-contrast viewing requires? Can electronic circuits be molded into their housings in a way that minimizes those cranky hand paddles and their moisture-sensitive connections to the RA and dec drives?
If we think through the improvements we want ahead of the manufacturers—maybe with a dose of optical math and design sketches thrown in—we, not they, would have the upper hand in product intros. Yes, all this is way ahead of the 3-D printing affordability curve at the moment. But isn't this the best time to dream up all the good-better-bests we can and let the manufacturing community know how many of us there are?