Bob, try also ANTARES, out of Vancouver, IIRC. They have ads in the back of the magazines. They carry the Vixen line of objectives, in both "Research Grade" and "Commercial Grade". I have purchased 2 Vixen objectives, found them both to be excellent. I have also purchased many objectives from Apogee, but the quality has varied. I think they have multiple sources, which might explain the inconsistency. Some have been excellent, some only fair. Kind of a crapshoot. You are correct in assuming that, with doublets, the longer the focal ratio, the less apparent the spurious color is. Folded refractors are a great convenience. Use the highest-reflectivity mirrors available to mitigate throughput loss. Chuck --- Marilyn Smith <bob-marilyn@worldnet.att.net> wrote:
After re-reading a few articles in S&T about folded long F.L. refractors, I'm toying with the idea of making one. Apogee lists a 90x1000 objective for $85, but they are out of stock until March. I'm leaning toward this 90 mm lens because I have a lens cell that I think will work, but my understanding is that a longer F.L. would have less color.. The only other source of objectives I have found is Surplus Shed, but their website doesn't list anything within a couple of inches larger or smaller. Does anyone know of other sources for objectives between 80 and 100 mm? Has anybody built a folded refractor? What kind of quality can I expect from Apogee lenses?
Bob Grant
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