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Message: <blockquote data-quote="WJC" data-source="post: 3160676" data-attributes="member: 25191">Etudiant et alFirst, thank you Etudiant; you’re very kind.I support your interest in unobstructed systems, and need not look at any internet sites to see what CAN be done. Also, I was corresponding with Jose Sasian before he got his PhD in optics, have been a friend of Dick Buchroeder from the 80s and the late John Gregory since the 70s. Further, you may note ATM Journal had off-axis systems sprinkled throughout, and that the SECOND article in my first issue of ATMJ was on off-axis systems.Binastro: you said, “There is nothing very difficult about making fast mirrors if the design requires it.” That was spoken like a fellow who had read a lot, but who had never really made one. I mean no offence, whatsoever, but I think you should make, say, a good f/2 system and then report back to us. I have made over a dozen mirrors, from 6 to 12.5 inches in aperture, and I would as soon kiss an Eastern Diamondback on the lips as start such a project. The same would have been true 30 years ago.All: It would seem that when the REALITY of a MASSIVE central obstruction for a fast mirror was revealed, who hadn’t considered that little contrast robbing reality, shifted to off-axis—pie in the sky—talk.Folks, we’re talking about HAND HELD binos; what is there to be gained? Then, perhaps you could share the magnitude of improvement over conventional wisdom that will make all the additional work, testing, and other considerations worthwhile.During a boat ride to Catalina, I had a conversation with Alan Hale, co-founder and then CEO of Celestron, (Oops, there I go name dropping, again. I dare not say he’s a friend, lest I really tweak the A-types) about why the cost of the C-5 was nearing that of the C-8. The reason:“The C-5 is much harder to make than the C-8 … it’s because of the size.”I thoroughly agree that conversations such as this one should be ALWAYS going on; it’s how we have advances in the art. However, it is only the thoughts that slip through the net of reason that will improve the art. I believe, further, optical and business realities should be liberally sprinkled, throughout such conversation.I once had a 16-inch SCT (f/.5 primary). That would put all the rays of the visible spectrum into a miniscule portion of the Airy Disc (at the edge of the field). It was waterproof and only weighed 3 pounds. I was VERY proud of it. Then, the alarm went off and I had to take a shower and get to work. :t:Cheers,Bill</blockquote>

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