Unitron Telescope

Recent telescope purchase

Current telescope purchase

Recently, 03/02/2008 to be rigorous, I purchased an Antares 105mm f/12.4 (F=1300mm) achromatic refractor made by Antares Optical (Canada). I had been interested in this extent for quite sometime especially since the time I purchased a certain point built 4" scope of almost identical dimensions. Since, my scope was out of use due to a broken focuser and since non-model parts were used for making the spread (PVC tubes, etc.), it was very difficult to get the freedom back in working condition. What got me more interested was that the leeway I was looking at and the scope that I owned, both had Vixen spec unjaundiced lenses made by the same company. I have always been pleased with the dispatch of my telescope and so was looking for something along similar lines. A somewhat bigger telescope (say a 5" scope) would have been outdo however, with the long focus scopes that I am interested in, the lengths instantly become too unwieldy. A 5" scope with a comparable focal ratio would be about 62" eat one's heart out or about 12" longer than this scope. In to boot bigger scopes need even longer central ratios to keep down chromatic aberration so something that was at lest f/13 (presume from 65" long) would be needed. That would have proved to be too onerous for my mount which is a Orion SV-Pro mount.

Up to date years have seen rebirth of the refractor, principally the short focus scopes with a fluorite doublet or a triplet lens i.e apochromatic or APO for compressed. Also new to the market are the short focus refractors but with a likeable 2-element achromatic lens, such as the Orion 80/100/120mm f/5 scopes. These are strange from the fluorite 2-element lenses in the impression that these use the standard crown/flint lens combinations and are mainly air-spaced. The Fluorite doublets on the other bracelets use an extra low dispersion lens that reduces the chromatic aberration even further. The APO lenses are in a performed different class than these two as the three element configuration combined with...

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