Old 14-09-2020, 02:19 PM
AusS2000 (Wayne)
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Location: Mosman
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Celestron 8-24mm eyepiece

Interesting in feedback on the Celestron 8-24mm eyepiece. I have the standard 40mm eyepiece that came with the scope and a decent 25mm. The 15mm that came with my Evo 6 has a really small pupil.

If the 8-24 has a decent pupil and eye relief and produces a good image it could be just the thing. If not, I'm probably just wasting my money (again).
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Old 14-09-2020, 02:56 PM
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Outcast (Carlton)
Always gonna be a NOOB...

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Join Date: Oct 2008
Location: Cairns, Qld
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I have one of these, it's okay. I find the eye relief to be reasonable, views are reasonable but, I wouldn't call it a stand out performer.

I mainly used mine on a solar scope & found it useful in not having to faff around changing EPs.

I have used mine for some night time observations but, tend to use my fixed FL eyepieces which are of considerably higher quality (& price tag).

Not a waste of time for the money but, you need to consider your expectations in terms of a budget zoom EP. If you are set on getting a zoom EP for the convenience & want high quality views I'd be looking at the Baader zoom but, they are substantially more expensive...

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Old 14-09-2020, 04:11 PM
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astro744 is offline
Join Date: Apr 2007
Posts: 885
Exit pupil = eyepiece focal length / telescope focal ratio.

For 15mm eyepiece and f10 telescope, exit pupil =15/10 = 1.5mm

For zoom at 15mm setting it will be the same. May have click stop at 16mm in which case it will be 1.6mm. At 8mm setting exit pupil will be 0.8mm.

Exit pupil determines the brightness of the image. 0.8mm is good for planets giving 187x in your telescope. If the image is too dim for your eyes with 1.5mm exit pupil then it will be even dimmer at 0.8mm. In your telescope 1.5mm exit pupil is 100x magnification.

Note exit pupil also = aperture / magnification.

The only way to get a bigger exit pupil in your telescope is to lower the magnification which is not ideal for planets going below 100x. If you want a bigger exit pupil and higher magnification then you need a larger aperture.
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Old 15-09-2020, 01:15 PM
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Max Vondel (Peter)
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Join Date: Aug 2008
Location: Sydney, Australia
Posts: 311
I had one but ended up selling it as at 24mm it was more like looking through a toilet roll due to its narrow field. Image quality ok.
Mine never got used
I think you are better off with a dedicated EP with the eye relief you need
There are quite a few economy options out there for under $200-
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