Vivitar 60x/120x lenses

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Vivitar 60x/120x lenses

Postby Carlosprince » Sun Apr 17, 2016 8:34 am

I have a 5mm lens and a 10mm lens. My last telescope had 3 lenses . which one am I missing?
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Re: Vivitar 60x/120x lenses

Postby Aratus » Sun Apr 17, 2016 4:04 pm

Probably a wide angle eyepiece.
I assume that your 5mm eyepiece is giving you a magnifiction of 120x so your focal lenth is 600mm (5x120).
Something like a 15 mm eyepiece would give you (600/15) 40x.
A 20mm eyepiece would give you (600/20) 30x
A 25mm eyepiece (600/25) = 24x

We would need to know the aperture (diameter) of the telescope to work out the largest eyepiece to use. You will then have a good range.
I use an 11" reflector (Celestron CPC 1100) and a 3" refractor, (Sky-Watcher ST80) mounted on an equatorial wedge, housed in a 2.2m Pulsar observatory. I use a ZWO ASI 120MM, ZWO ASI1600MC and Canon 1300D for imaging.
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