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Old 14-05-2015, 01:43 PM
Renato1 (Renato)
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Join Date: Mar 2014
Location: Frankston South
Posts: 1,283
The 130p is a 5.1" diameter telescope and has 650mm focal length and an f/5 focal ratio.

So 10mm eyepiece gives you 65X and a 2mm exit pupil, which is the ideal eyepiece for looking at faint Deep Sky objects, but too low a power for planets.

With a properly collimated telescope and good seeing conditions, I expect the telescope should be able to hold 250X on some nights of the year - which translates to a 2.6mm eyepiece (i.e. a 5mm eyepiece in a 2X barlow, or a 6.5mm eyepiece in a 2.5X Barlow, 8mm eyepiece in a 3X Barlow).

But for most nights, I'd expect around 200X would be better, which translates to a 3.25mm eyepiece (i.e. a 6.5mm eyepiece in a 2X Barlow, or an 8mm eyepiece in 2.5X Barlow or a 10mm eyepiece in a 3X Barlow).
If you go for the lower power option, remember that you can increase magnification by around 10% by keep the eyepiece further out of the Barlow, rather than pushing it all the way in.

I don't know how good your eyepieces are - often the ones that come with telescopes may be mediocre.

My suggestion is to just be patient, and wait for either a very good eyepiece or a good Barlow that meets the parameters above, to show up in the classifieds.
Regards,
Renato
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