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Message: <blockquote data-quote="WJC" data-source="post: 3166564" data-attributes="member: 25191">Hi All:Owing to all the interest in catadioptric and off-axis binoculars that I have seen posted here, I might suggest that interested forum members contact the Big Three and tell them they are foolish for not making such. I would only offer a word of caution relating to the hurdles they will have to surmount to put them into production.1. You will need to show mathematically ($$$$) how such a system would provide a SIGNIFICANTLY better image than could be produced with a state-of-the-art in conventional binocular. And why the AVERAGE observer should even care.2. For either Cassegrain or off-axis binoculars, you will need to prove to them that collimationally finicky systems, could be made to be infinitely more rigid than with current technology. Of, course they could be active systems and IS systems. But then, you would need to prove that Aunt Myrtle, and her bird watching friends, can—and WOULD—spent $20,000+ for the electronic and mechanical ad-ons, as well as providing a muscleman for each lady to hold the binocular up to their eyes.3. The companies might also question the cost of the additional floor space required to house the additional lenses, prisms, mirrors, fixtures, and test equipment that weren’t needed … last year. 4. You would need to prove the headaches that come with making the various relay lenses and mirrors would be financially worth the effort. 5. Although you might enjoy the images from a system with a large central obstruction (with some not realizing what that means to an image), I feel trying to sell that idea to any one of the Big Three might elicit a great deal of laughter, after which they might show you a photo of a star field taken with an apochromatic refractor, in which stars looked like pinpoints, and another taken with an obstructed system in which the stars look like they were drawn with a crayon. Then, when you protested, they might show you that the better of the photos taken with SCTs, were taken with the corrector fitted with and off-axis mask. And please, don’t now jump on the off-axis band wagon; it’s just as foolish, and concerns itself with cheap Asian instruments that are targeted to those who are incredibly inexperienced.It’s KNOWLEDGE that lets you know the tomato is a fruit.It’s WISDOM that lets you know you shouldn’t put it in a fruit salad!Thoughts like those flourishing on this thread can be very helpful when participants have a knowledge of the realities of lens design and the realities of instrument production.Until then, I would encourage any member to make such an instrument as has been discussed thus far, and send it to Zygo that the benefits might be documented in an authoritative way.Bill (your warm and fuzzy little curmudgeon) out |:x|PS Once while working on an issue of ATM Journal, I received an article with the sender raving that he had designed a telescope in which ALL the rays fit into a TINY, TINY segment of the Airy disc. Along with the article, he sent me a spot diagram of his work. [In those days, Ray fans, OPD plots, and MTFs were out of the question for amateurs.] This, of course, was too good to be true. Yet, this telescope maker was too excited to pay any attention to that negative and frivolous reality. And, I’m sure all his telescope making buddies were duly impressed.With a little investigation, however, it was easy to see he how he had designed such a superlative system … HE DESIGNED IT AROUND ONLY ONE WAVELENGTH!When I took his specs and dropped in the red and blue—he had designed it around .580 microns—it would have taken a bank of it least 9 monitors to capture all those rays. The system that was so wonderful in his head was worse than useless in the real world.Was this a bad person? Of course not. He was just ignoring one of the most basic procedures in designing lenses. Reality bites, and I think a person who points out such folly is doing a favor, at least to those who care about the truth.</blockquote>

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