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barlow, eyepiece, eyepieces, luminos, magnification, plossls, seeing -

When you’re selecting a new eyepiece, the first and most important consideration should be how it fits in with the eyepieces you already have – particularly, your magnification scheme.  To figure out the magnification of your eyepieces, you take the focal length of your telescope (1200mm for an f/6 8-inch dob) and divide it by the focal length of the eyepiece.  For example, if you have, say, 25mm and 10mm Plossls that came with your 8-inch dob, they’re giving you 48x and 120x respectively. So, the first analysis is to fill in magnification “gaps” you have – like a high-powered eyepiece,...

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