33 replies to this topic

[MaximusStarHunter]

Hello, I have an 8” Skywatcher classic dobsonian. I still have the eyepieces that the scope came with. I am wondering what the best eyepiece to get would be for viewing galaxies, like Andromeda and Whirlpool. And the best nebula in the sky. It would also be great if they could see the open and globular clusters. I feel that I could get alot more details out of the things I see with an upgrade. And please keep it not too costly. Not hundreds of dollars please.

 

Thanks, Maximus

[f74265a]

For andromeda, binoculars under a dark sky is the best way. It’s huge— roughly 6 full moons wide.

[YeloSub]

Those are very different targets. Looking at Andromeda you want a lower power eyepiece as it is a very large object. But for pretty much every other galaxy, those are much smaller and would require higher power (shorter Focal length eyepieces)

Your budget is what really matters here... how much are you willing to spend per eyepiece? On that note I would personally budget for 3 good eyepieces. You can fill in the gaps and get more later as you get more experienced and understand what you want/need.

For your 8" dob I would recommend getting something in the 24-28mm range, 12-14mm, and 6-8mm. But start your investment with the low power first.

Give us your budget and then we can help narrow down your choices.

[MaximusStarHunter]

Thank you, my budget is less than 100 hundred. Preferably not too much. Would anybody have any specific brands and studd. And with nebulae, I mean like ring nebula, dumbbell, and many other great ones. Also for globular clusters, like the hercules one, and many others. Also open clusters like the beehive and others. Thank you.

[NiteGuy]

For starters, as a good all-around choice for what you've described, my choice would be the currently out-of-stock Astro-Tech 8mm 1.25" Paradigm Dual ED eyepiece for $65.00 (look for a pre-owned one on CN Classifieds or AstroMart). What you're asking for is what I spent many years looking for and that's the "perfect cheap eyepiece." Consider that to be a quest for "unobtanium". After more than a half-dozen of the cheapies, I bought my first TeleVue Nagler eyepiece, a 9mm, and never looked back.

 

With your 8", the 8mm Paradigm will provide 150x. That will nicely resolve globular star clusters and at that magnification it will provide better contrast than your 10mm Kellner for objects like galaxies and nebulae.

 

From a very dark sky and using averted vision, you should be able to detect M51's whirlpool shape. Other objects like the M8, the Lagoon Nebula, and M17, the Swan Nebula, the Veil Nebua, the Double Cluster, planetary nebulae like M27 the Dumbbell Nebula, M57 the Ring Nebula, and galaxies like M81 & M82 will all be pretty vivid at 150x. The king of the winter skies, M42 the Orion Nebula, will show amazing detail at 150x with your 8-inch scope. Save higher magnifications than that for the Moon & planets.

 

Next up after the 8mm, you might want to add a 2x Barlow lens. That will double the power of all your eyepieces, providing 96x with your 25mm, 240x with your 10mm, and 300x with your 8mm. You'll never need more than that. If you really enjoy astronomy and observing, you will eventually want higher quality eyepieces with wider fields of view, more comfortable eye relief distance, pin-point stars to the very edge of your field of view, and sharper details with more contrast. Great eyepieces can transform any observing experience but they do come at a typically painful price. Today, my favorites are the Baader Morpheus eyepieces.

[MaximusStarHunter]

For starters, as a good all-around choice for what you've described, my choice would be the currently out-of-stock Astro-Tech 8mm 1.25" Paradigm Dual ED eyepiece for $65.00 (look for a pre-owned one on CN Classifieds or AstroMart). What you're asking for is what I spent many years looking for and that's the "perfect cheap eyepiece." Consider that to be a quest for "unobtanium". After more than a half-dozen of the cheapies, I bought my first TeleVue Nagler eyepiece, a 9mm, and never looked back.

 

With your 8", the 8mm Paradigm will provide 150x. That will nicely resolve globular star clusters and at that magnification it will provide better contrast than your 10mm Kellner for objects like galaxies and nebulae.

 

From a very dark sky and using averted vision, you should be able to detect M51's whirlpool shape. Other objects like the M8, the Lagoon Nebula, and M17, the Swan Nebula, the Veil Nebua, the Double Cluster, planetary nebulae like M27 the Dumbbell Nebula, M57 the Ring Nebula, and galaxies like M81 & M82 will all be pretty vivid at 150x. The king of the winter skies, M42 the Orion Nebula, will show amazing detail at 150x with your 8-inch scope. Save higher magnifications than that for the Moon & planets.

 

Next up after the 8mm, you might want to add a 2x Barlow lens. That will double the power of all your eyepieces, providing 96x with your 25mm, 240x with your 10mm, and 300x with your 8mm. You'll never need more than that. If you really enjoy astronomy and observing, you will eventually want higher quality eyepieces with wider fields of view, more comfortable eye relief distance, pin-point stars to the very edge of your field of view, and sharper details with more contrast. Great eyepieces can transform any observing experience but they do come at a typically painful price. Today, my favorites are the Baader Morpheus eyepieces.

So that isn’t too much magnification?

[MaximusStarHunter]

We could go some over 100 dollars so it can just be a long term deal.

[25585]

What do viewers in the Southern Hemisphere use to study the Magellanic Clouds?

[YeloSub]

With that budget, the paradigm 25mm, 12mm, and 8mm will serve you well. Adding the 5mm later as budget allows. Or maybe even adding a x2 barlow.

[MaximusStarHunter]

With that budget, the paradigm 25mm, 12mm, and 8mm will serve you well. Adding the 5mm later as budget allows. Or maybe even adding a x2 barlow.

Which would be best for general nebula and galaxies?

[YeloSub]

Check out this website:

https://astronomy.to.../field_of_view/

Will show what an object will look like with a particular telescope and eyepiece. Give you info such as FOV, magnification, and exit pupil.

[NiteGuy]

So that isn’t too much magnification?

Well, you didn't say what kind of skies you have where you live so I'm saying that 150x would be PERFECT IN DARK SKIES with your 8". That goes for open star clusters, globular star clusters, nebulae, planetary nebulae, and galaxies. If you live in the middle of a city, then you won't be seeing much of anything worthwhile, except Moon & planets.

 

With an 8mm Paradigm eyepiece, you'll have a 0.4 degree field of view at 150x. The Moon, on average is 0.5 degrees in diameter. So, while it won't be enough to get the entire Andromeda galaxy in the field of view, it will be GREAT for everything else. Might be a bit much for planets and the Moon if the seeing conditions are really turbulent but, with decent seeing conditions, 150x is a nice amount of power.

[Lizardman]

Buy good quality eyepieces. You truly do get what you pay for. Go cheap and you’ll miss a lot. So my thought to put you in the middle but slightly above your budget; 28mm Astrotech from Astronomics if your scope can take a 2” eyepieces.

Edited by Lizardman, 05 November 2024 - 07:37 PM.

[MaximusStarHunter]

Buy good quality eyepieces. You truly do get what you pay for. Go cheap and you’ll miss a lot. So my thought to put you in the middle but slightly above your budget; 28mm Astrotech from Astronomics if your scope can take a 2” eyepieces.

It can, thank you.

[Dobs O Fun]

With the same scope you and I shared I have the Celestron XCel-LX in 25, 18 and 5 and it does well. The others mentioned in this thread are great as well.

Yes I can go more expensive but my light polluted skies are a limiting factor.

[Sketcher]

There is no one best eyepiece for those purposes.  Best is to have a variety of eyepieces so that you're able to see what different objects look like at different magnifications, on different nights, from different locations, etc.  Then you can decide which eyepiece provides you with the view that you prefer.  On a different night, you might prefer the view provided by a different eyepiece -- even when using the same telescope to observe the same object.

 

At the bare minimum you'll want a low, a medium, and a high-power eyepiece.  After that, you'll want to gradually fill in areas that you determine need to be filled in -- in between magnifications, etc.  Add another eyepiece when you have a specific need for another eyepiece -- when you know what attributes you want in a different eyepiece.

 

Wanting the best eyepiece for galaxies and nebulae just doesn't cut it.  What magnification do you want?  What true field of view do you want?  What apparent field of view do you want?  What exit-pupil do you want?  How much eye-relief do you want?

 

There's no need to go out and buy a bunch of eyepieces right away.  Start by making good use of what you have.  Add another eyepiece when you feel the need for another eyepiece that can provide you with what you want (a certain field of view?  a certain magnification? etc.) that the rest of your eyepieces are unable to provide.  Over time, you'll end up with a wide enough variety of eyepieces that you'll be able to try different eyepieces on an object in order to decide which one provides you with your preferred view of that object.

 

With all that being said:

 

My best guess is that what you really need in order to get the views you want of galaxies and nebulae (assuming that the views you want are attainable) is the opportunity to use your telescope under a seriously dark sky with seriously dark-adapted eyes and with an experienced eye-brain system.  Those three things are more likely to provide you with the better views that you're wanting than buying another eyepiece.

 

But yeah, it's still a good idea to have a wide enough selection of eyepieces to be able to fine-tune the best magnification, etc. to use on a particular object at a particular time from a particular place, etc.

Edited by Sketcher, 07 November 2024 - 01:11 PM.

[Bill Barlow]

I look at the size of the exit pupil when viewing galaxies, nebulae and GC’s.  For me, the best range is to use eyepieces that yield EP’s of 1.5 to 2.5mm.  I use these mostly in my C8, which means I frequently use the 24mm Panoptic, 20mm XW, 16mm Nagler, 14mm XW and sometime the 12mm Delos.

Edited by Bill Barlow, 09 November 2024 - 11:30 AM.

[MaximusStarHunter]

I look at the size of the exit pupil when viewing galaxies, nebulae and GC’s.  For me, the best range is to use eyepieces that yield EP’s of 1.5 to 2.5mm.  I use these mostly in my C8, which means I frequently use the 24mm Panoptic, 20mm XW, 16mm Nagler, 14mm XW and sometime the 12mm Delos.

If you could pick one would it be a 25mm, 18mm, or 12mm?

[Dave Mitsky]

If you could pick one would it be a 25mm, 18mm, or 12mm?

Your telescope has a focal ratio of f/5.9 and a focal length of 1200mm, which means that a 12mm focal length eyepiece will produce 1200mm/12mm or 100x at an exit pupil of 12mm/5.9 or slightly more than 2mm.  A 2mm exit pupil is useful for observing many deep sky objects.  However, there's not a lot of difference between a 12mm eyepiece and the 10mm one supplied with the telescope, other than the possibility of a wider apparent field of view and enhanced eye relief.

https://www.celestro...ossary-of-terms

[Dave Mitsky]

While it doesn't deal with using a telescope directly, you may find some of the information on astronomy, amateur astronomy, and observing presented in my post (#22) at https://www.cloudyni...mers/?p=5184287 useful, MaximusStarHunter. There are sections on various books, observing guides, the Moon, the planets, star-hopping, stellar atlases, planispheres, planetarium programs, astronomy apps, deep-sky objects, lists of worthwhile celestial objects to observe, binocular astronomy, urban astronomy, and other related topics.

[MaximusStarHunter]

Your telescope has a focal ratio of f/5.9 and a focal length of 1200mm, which means that a 12mm focal length eyepiece will produce 1200mm/12mm or 100x at an exit pupil of 12mm/5.9 or slightly more than 2mm.  A 2mm exit pupil is useful for observing many deep sky objects.  However, there's not a lot of difference between a 12mm eyepiece and the 10mm one supplied with the telescope, other than the possibility of a wider apparent field of view and enhanced eye relief.

https://www.celestro...ossary-of-terms

Yeah, because I was just planning on buying on eyepiece to start with (due to budget) and was wondering which would be the best for a wide area of objects. Like nebula, and globular clusters and open clusters and galaxies. Like a size that will show me the most of the objects that I want to see. So you say that 12mm is the best for that?

[Tropobob]

What do viewers in the Southern Hemisphere use to study the Magellanic Clouds?

I enjoyed looking at the SMC with an ED Orion 80mm F6 teamed with a TV 24mm Panoptic.  I could just fit it all in.  It's really amazing from a location with dark skies.  

 

Only binoculars could fit in the LMC, but this was really too low a power to be really impressive. 

[Dave Mitsky]

Yeah, because I was just planning on buying on eyepiece to start with (due to budget) and was wondering which would be the best for a wide area of objects. Like nebula, and globular clusters and open clusters and galaxies. Like a size that will show me the most of the objects that I want to see. So you say that 12mm is the best for that?

There are many hundreds of DSOs that are potentially visible, and they vary considerably in apparent or angular size and in apparent magnitude.  For example, you mentioned M57 (the Ring Nebula) and M44 (the Beehive Cluster), which are approximately 1.5 by 1 arc minutes and 95 arc minutes in apparent size respectively.  (Many planetary nebulae are smaller than M57, by the way.)  M57 will look rather small using a 12mm eyepiece (100x) and M44 will be too large to fit entirely into the true field of view produced by that eyepiece.  So, it all depends upon the object in question but since most DSOs are rather small in apparent size a 2mm exit pupil will work for many of them.

 

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[Dave Mitsky]

Here's another simulated field of view, this time featuring the globular cluster M13 in Hercules, from https://astronomy.to.../field_of_view/
 

I used a 12mm eyepiece with a 60-degree apparent field of view like the 12mm Celestron X-Cel XL.

Keep in mind that telescope simulations can be a bit misleading.

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[YeloSub]

There is a 12mm Paradigm in the classifieds right now for $35.