I have a celestron powerseeker 114eq telescope. Aperture : 114mm Focal Length: 900mm

I have 20mm and 4mm eyepieces and a 3x Barlow. I have seen Saturn's rings using 4mm eyepiece but it's blurry and with 3x it becomes impossible to see any detail. With 20mm with 3x barlow they are too small. I found a kit on amazon with 6mm and 12.5mm kellener eyepieces with a moon filter. I wanted to view a little larger than 20mm with 3x barlow and with details like color contrasts. Could anyone tell whether the kit that I found will be useful or anything else to suggest to solve my problem?

  • $\begingroup$ The answer depends on your location and how good the seeing usually is there. Alternatively, you could get a zoom eyepiece, and that way you can push the magnification as high as the seeing will allow without having to switch eyepieces. $\endgroup$ – Aaron F Oct 6 '20 at 23:27
  • $\begingroup$ Also, bear in mind that your 20mm with 3x Barlow is effectively a 6.67mm eyepiece. The 6mm you're considering getting won't be a huge difference. $\endgroup$ – Aaron F Oct 6 '20 at 23:57
  • $\begingroup$ If my location is the case then I live in India, Hyderabad. also I wanted to ask from where could I get a zoom eyepiece, like from which website? $\endgroup$ – RyugaGod Oct 7 '20 at 2:56
  • $\begingroup$ It's generally quite humid there, which will negatively affect seeing, as will the Earth's jet stream. Bookmark this website - meteoblue.com/en/weather/outdoorsports/seeing/… - it'll give you an idea of what the conditions will be like for the next few days. $\endgroup$ – Aaron F Oct 7 '20 at 8:55
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    $\begingroup$ Thank you very much Aaron, you are very helpful👍. $\endgroup$ – RyugaGod Oct 7 '20 at 9:36

I find a zoom eyepiece and Barlow to be useful for viewing planets.

Depending on your location, seeing can be very variable, sometimes changing from one second to the next.

A zoom eyepiece lets you adjust the magnification without switching eyepieces, so you can quickly adapt to the changing seeing conditions.

The downside of zooms is that they tend to have narrow fields of view.

I use an 8mm-24mm zoom eyepiece with a 3x Barlow, effectively giving a 2.67mm-8mm zoom, which is a great magnification range for looking at planets.

Make sure you take your time and keep watching the planet, watching for those split-second moments of crystal-clear seeing, and absorb the extra detail you can see in those small windows of opportunity. It's in those moments that you really see the planet.

Also, bear in mind that Saturn will look quite small, especially if you've just swung over from looking at Jupiter; it's almost as big as Jupiter, sure, but it's almost twice as far away as Jupiter is.

  • $\begingroup$ Thanks for the reply. I find this to be helpful. I live in India, Hyderabad. So would this zoom eyepiece be useful, also if yes then from which website should I purchase? $\endgroup$ – RyugaGod Oct 7 '20 at 2:58
  • $\begingroup$ also, would this be a good buy? desertcart.in/products/… $\endgroup$ – RyugaGod Oct 7 '20 at 3:07
  • $\begingroup$ That zoom is a generic model. Quality will be variable (two 'identical' eyepieces will perform differently). In that price range I would personally buy the Orion E-Series 7-21mm, as I've heard it provides good value for money. A good mid-priced zoom would be the Pentax 8-24mm or Baader 8-24mm. A good top-end zoom is the Leica 25-50x WW ASPH. $\endgroup$ – Aaron F Oct 7 '20 at 8:30
  • $\begingroup$ Even if every piece gives different result, would it improve my present situation because if so I would prefer buying it. $\endgroup$ – RyugaGod Oct 7 '20 at 9:47
  • $\begingroup$ @RyugaGod it's totally up to you, but if you found this answer good enough to accept, you can also consider up voting it. Usually it's the other way around, we upvote helpful answers even if we don't accept them. Of course it's your choice, I see that you are new to Stack Exchange and just wanted to let you know about it. $\endgroup$ – uhoh Oct 7 '20 at 15:25

From my limited experience, being able to see the rings on Saturn is more or less the extent of how powerful eyepieces can get for a home telescope. To get better and larger images would require a better and probably larger telescope.

  • $\begingroup$ Thanks a lot, but I wanted to make do the best possible outcome with my existing scope. So if possible could anyone suggest an eyepiece for a better outcome than my existing situation or whether a 6mm eyepiece would be the way to go? Thank you. $\endgroup$ – RyugaGod Oct 6 '20 at 16:54

Your Exit Pupil for your scope is too small with a 3mm eyepiece.

Exit Pupil = Focal Length of Eyepiece / Focal Ratio of Telescope

3mm/7.89 (your scope focal ratio) = 0.38mm

You need a minimum of 0.5mm to 0.7mm, therefore a minimum of 4mm focal length eyepiece.

The maximum power is roughly 2 x 114 = 228X.

You can use this site to get a glimpse of what you can see in your scope: https://astronomy.tools/calculators/field_of_view/



  • $\begingroup$ Ok thanks 👍🏻🙂 $\endgroup$ – RyugaGod Feb 5 at 5:40

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