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Starbase 'Orthoscopic Plossls' Revisited

Discussion in 'Eyepieces, Barlows, and Filters' started by Mak the Night, Dec 24, 2021.

Starbase 'Orthoscopic Plossls' Revisited

Started by Mak the Night on Dec 24, 2021 at 3:28 AM

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  1. Mak the Night

    Mak the Night Well-Known Member

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    The Starbase O/PL’s were originally acquired for my 102mm Sky-Watcher SkyMax MCT. Its focal ratio of f/12.7 should ameliorate any aberration problems that were noticed in the faster 72ED. The initial rationale behind buying these eyepieces was that they were relatively light in weight, ergonomic (I like volcano tops), and had good build quality. The whole SkyMax grab and go kit needed to be light and portable and fit into a small holdall-type bag. I’ve owned the 102mm StarMax for a long time and tend to predominantly use it as a lunar grab and go scope.

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    The 20mm Starbase gave me a nice view of Saturn and Jupiter at 65x. It was when I started using the 14mm it started getting interesting. Although I did notice the undercut snagging occasionally when swapping eyepieces. The three screws of the Baader helical compression ring can often be a little finicky with barrel undercuts. The 14mm O/PL gave a fairly sharp 92.8x. The seeing was above average, but not as good as the previous night.

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    Jupiter’s GRS was just noticeable near the western limb and would be about central at transit (03:20 British Summer Time). Ganymede, Callisto, and Io were close together on the western side of the planet with Europa on the opposite side. I could perceive colour in the moons and discern some Jovian surface detail. As the planet rotated the GRS became more easily visible.

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    I decided it was time for the 9mm ‘Orthoscopic Plossl’. At 144x I lost a lot of acuity and furthermore there appeared to be quite noticeable ghosting. Jupiter is very bright at the moment though with a visual magnitude of -2.8. Inevitably I switched back to the 14mm and even the Orion zoom for a while. I still couldn’t manage much above 100x though. Saturn fared better with the 9mm but even then I didn’t think it was as sharp as it could have been. This was probably more to do with conditions than anything else. When Jupiter reached transit I still wasn’t satisfied with the 9mm although around an hour later I had a much sharper view at 144x

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    In a later outing I decided to have a dedicated lunar session with the 102mm SkyMax and the Starbase Plossls. The Moon was high and conditions were good. I have to say I was not overly impressed with their performance. The 9mm exhibited so much ghosting I seriously considered contacting Yvette Fielding and the team at ‘Most Haunted’. Even the usually reliable 6mm had some slight but quite noticeable ghosting and they all had serious scatter issues. I can only attribute this to the Kubota Optical Corporation single coatings.

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    In a direct comparison with some equivalent focal length generic Chinese Plossls and the Orion 7~21mm zoom the inexpensive Plossls displayed excellent results, as did the Orion zoom. Perhaps the Starbase eyepieces would perform better in a slow refractor. I think that they can be very good for deep sky or splitting doubles, but for dedicated lunar viewing they are an epic fail.
     
    Last edited: Dec 24, 2021
  2. Mak the Night

    Mak the Night Well-Known Member

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    Now with smoothies.

    [​IMG]
     
  3. Mak the Night

    Mak the Night Well-Known Member

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    Even with smoothies they're still a fail.
     

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