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  1. R

    Star Testing

    @Binastro Thank You, for your reply. The only means of boosting the magnification on my spotting scope is with the factory 1.8 extender. This takes the highest magnification to 90X for the 82mm objective (0.91 EP). Would this magnification be sufficient to star test this instrument? Thanks, Randy
  2. R

    Star Testing

    I went back and re-read the first paragraph of your reply and please forgive my endless questions but, can I assume that you would not purchase a new scope if you did not have the opportunity to both: compare the view through the new scope to your astro-physics and also perform a star test with...
  3. R

    Star Testing

    @henry link Thank You, for your reply. What do you reference to determine if a aberration is moderate or mild? If a star test is not conducted properly (by someone like me who lacks the experience) could the test results reveal an aberration that doesn’t really exist or make a mild aberration...
  4. R

    Star Testing

    @Binastro @jring I would like to extend the above question, for Mr. Link, to you guys. Thanks, Randy
  5. R

    Star Testing

    @henry link Thank You, for your response. Based on your experience, and owning a very good reference scope, can you view normally through a new scope, and then, kind of predict what the star test will probably reveal? If so, have you ever been surprised? Thanks, Randy
  6. R

    Star Testing

    @jring Thank You, for your response. I was only somewhat aware of who Mr. Christen was. The intent of my question was more technically motivated. I was interested to know if it was possible for someone like Mr. Christen to perform hand aspherizing on a spotting scope or, if there exists design...
  7. R

    Star Testing

    @Binastro Thank You, for your response and, please forgive another amateur question: Do you think it would be possible for Mr. Christen to perform the “local polishing”, that he mentions, on a spotting scope to achieve a better star test or, does this only pertain to fast APO triplets? Thanks...
  8. R

    Star Testing

    @Binastro Is this what Mr. Christen was referring to with this statement: “The dilemma for manufacturers then is, should we do our best to produce smooth high contrast optics, or should we please the star test crowd and do some hand aspherizing to get a more pleasing out-of-focus star image? I...
  9. R

    Star Testing

    Thank You, @Binastro and @jring I think I have somewhat better understanding now but no where close to where I would like it to be. When I read the above article the first impression I got was that Mr. Christen does not put much faith in the results obtained when star testing fast triplets...
  10. R

    Star Testing

    Thank You. From your reply can I assume that at normal spotting scope magnifications a poor star test may not effect your (in focus) view at all?
  11. R

    Star Testing

    This sentence from the above article is what I am having the most trouble with: “But for the fast F6 and F7 triplets I make now, the star test falls short.” I was under the impression that most spotting scopes are faster than F6 or F7.
  12. R

    Star Testing

    In another thread @jcwu88 posted two links by Roland Christen (Astro Physics): Notes on Star Testing Refractors Star Testing Complex Optical Systems I just purchased my first spotting scope and have never attempted a star test so, this is all new to me. Therefore I would really appreciate...
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