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Thread: question about my focal reducer and magnification

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    Default question about my focal reducer and magnification



    Could someone please explain to me by exactly how much my f6.3 focal reducer reduces the magnification of my 8" sct f10 scope.
    For example say when using a 8mm e/p.
    Scope = Celestron CPC800 8"sct. Sky-watcher Heritage 130p flex tube Dobsonian Binoculars = Helios Ultima 10x50 porro prism.
    Eyepieces = Baader Hyperion Aspheric 31mm and 36mm. Baader Hyperion 8mm, 13mm, 17mm, 21mm and 24mm.
    Diagonal = 2" Altair dielectric diagonal.

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    Default Re: question about my focal reducer and magnification

    The focal reducer has a ratio of 0.63. So your focal ratio goes from f/10 to f/6.3 (= 10 * 0.63), your focal length goes from 2000mm to 1260mm (= 2000 * 0.63). Because of the change in focal length, your magnification for each eyepiece is reduced by a factor of 0.63.

    Your 8mm eyepiece normally has a magnification of 250x (= 2000 / 8). With the reducer, it has a magnification of 158x (= 1260 / 8).

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    Default Re: question about my focal reducer and magnification

    That's great keith thank you for sharing your knowledge
    Scope = Celestron CPC800 8"sct. Sky-watcher Heritage 130p flex tube Dobsonian Binoculars = Helios Ultima 10x50 porro prism.
    Eyepieces = Baader Hyperion Aspheric 31mm and 36mm. Baader Hyperion 8mm, 13mm, 17mm, 21mm and 24mm.
    Diagonal = 2" Altair dielectric diagonal.

 

 

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