Old 19-11-2018, 06:43 PM
glend (Glen)
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Which one to keep?

As my clearance continues, I am now down to two imaging scopes: a TS80 f7 APO and the TS115 f7 APO. Which one to keep?
They both take the same 3" (0,79x) reducer corrector, and thus both run at f5,53 reduced. Regarding the colour correction, the 80 is an FPL-53 Doublet, and the 115 is a FPL-51 and Lanthanum Triplet (has a slight edge in performance, but is heavier of course).

So it comes down to focal length, weight, and correction. Opinions?
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Old 19-11-2018, 06:44 PM
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multiweb (Marc)
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TS115 f7 APO
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Old 19-11-2018, 07:08 PM
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Slawomir (Suavi)
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Same what Marc recommended. If carrying a 115 triplet is not a big issue, then it should be a more capable instrument for imaging due to being better corrected for field curvature (longer focal length) and most likely having smaller spot size than the 80mm one (larger aperture + triplet). It will also provide with more exciting views if used visually.
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Old 19-11-2018, 07:09 PM
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Atmos (Colin)
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If the 115mm weight wise isn’t going to be an issue I’d definitely go with that. Better colour correction and a bit more aperture is worth it if you can handle it
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Old 19-11-2018, 08:02 PM
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So long as you can comfortably manage the 115, I'd definitely stick to the 115.

But if your health is such that it is not so "fun", go with the 80.
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