5 Best Telescope Eyepieces in 2020 [+Beginner’s Guide]

Stargazing is an awesome part of astronomy. That’s where you witness at firsthand how all those deep sky objects look like, where they are, how big and bright they are. With the right equipment, you can enjoy the ever-fascinating night sky objects from the moon and the planets to deep-sky nebulae and galaxies.

In stargazing, eyepieces are as important as the telescopes are. Choosing the most appropriate can completely change your experience in using telescopes. Poorly chosen eyepiece might give you poor experience and sometimes even make stargazing difficult.

In this guide, I’ll introduce you to what to look for when choosing eyepieces for your scope. Right eyepieces will let you enjoy the night sky in all its glory.

We Recommend

Best for the money

Tele Vue 100° 13mm
Ethos Eyepiece

Has the ‘wow’ effect

Explore Scientific
68° 40mm Eyepiece

Best budget option

Meade Instruments
100° 10mm Eyepiece

Types of telescope eyepieces

  • Plossl – I guess this is the first type of eyepieces that you’ll get introduced to and you might even get them free with your scope. I don’t recommend these eyepieces at all. For an even smaller amount of money, you can get far better and higher quality eyepieces.
  • Kellner (achromatic) – These eyepieces are quite similar to plossls. They don’t give you a nice, wide field of view, and their eye relief is short as well.
  • Orthoscopic – These are known to have superior image quality even on edges, but unfortunately, these eyepieces are with the smallest apparent field of view, so you are not getting much of the surrounding area. Probably these are the eyepieces that were used by people with eyeglasses because of their large eye relief. I never recommend using glasses while stargazing, because you’ll get at least one external reflection of the light, plus some additional optical distortions due to lens misalignment. This design is best for observing close binary stars but not more than that.
  • Aspherical – This kind of eyepiece is, for sure, the best buy. They have good image quality with a fairly decent apparent field of view. They cost almost nothing, and that’s why everybody should own a piece or two of these. Aspherical eyepieces are better in almost all cases while stargazing than other cheaper designs.
  • Ethos, Nagler, Delos – These are the eyepieces to own; these are the eyepieces to save money for. Their superior design, image quality, and large apparent field of view make them superior to the rest. Nowadays, you can find nice, complex optics eyepieces for third of a price that was 5~6 years ago. But they are still 10 to 15 times more expensive than low-end eyepieces. If you invest more money in a larger 12”+ telescope, than one of these would be highly recommended.
  • Zoom eyepieces – These eyepieces are not that good. They tend to have an apparent narrow field of view. When you change their focal length (magnification), you must refocus the image. I would recommend these eyepieces only for use with smaller scopes, with a focal length smaller than 600 mm and apertures smaller than 6”. Nice and handy eyepieces for public observing events, so you don’t have to change eyepieces.
  • Planetary eyepieces – These eyepieces are low on light. It means you can observe only the brightest objects like the planets, the Moon and double stars.

What diameter eyepiece should you buy?

The diameter of your eyepieces depends only on what your telescope supports, or to be more precise, what your focuser supports. Most of the telescopes are made for 1.25” and 2” eyepieces with an interchangeable adapter. 10 years ago, there were some smaller scopes that were made for .965” eyepieces, but I guess now they are obsolete.

In my opinion, for a start, you should stick to one preferred barrel dimension. Because in the future, when you buy various expensive deep-sky filters, you wouldn’t like to buy them twice for 1.25” and 2” eyepieces.

Quick tip: You can try to mount the filters in front of the 2” eyepiece, or just leave them on top… until you buy filters for larger eyepieces.

In my experience, you need only two eyepieces 10 mm and 24 mm for 90% of the night sky objects, so make them match. I prefer 1.25” eyepieces mainly because they are more common and there is no price difference between the barrel sizes when it comes to eyepieces. But there is a price difference in the filters, most of the 2” deep-sky filters are almost double the price.

The problem comes when you would like to use a bigger eyepiece than 24 mm with a wider apparent field of view than they come only with 2” barrel width because they need to show more of the sky.

You can change the focuser of your scope to 3” barrel and get to mount those ‘windows to the heavens’ with 30 mm and 100° apparent field of view. But that might cost you a fortune.

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What focal length eyepieces should you buy?

At first, I would recommend one between 9 – 13 mm and one between 20 – 24 mm. Later you can purchase the 40+ mm eyepiece. So, maybe you are asking where the 3 – 7 mm eyepieces are. Those focal lengths are for the best telescopes 12”+ where you can utilize the greater focal length; hence you’ll get magnifications upward of 300X. Nice, quality sub 5 mm eyepieces are a bit pricey.

Each eyepiece gives you a unique magnification based on the formula: focal length telescope / focal length eyepiece = magnification. That means that if you own a telescope with 1000 mm and eyepiece 25 mm, you’ll get a magnification of 40X. 

Different sizes of eyepieces give you different magnifications, so you can observe different objects at appropriate magnification. Sometimes you want to see two or more close by objects in your field of view, that’s when you use larger eyepieces.

Calculate highest useful magnification

Well, I never liked this kind of ‘rules’ because they are completely off from what you experience when using telescopes. These kinds of specifications you can find in the technical details of the manufacturers, but according to my experience, they are far off the practical and useful magnification. Maybe that’s why you don’t hear these numbers in reality or at star parties.

Usually, when people are talking about the ‘highest useful magnification of a telescope,’ they are using a simple formula by multiplying the aperture in inches with 50. That means the ‘highest useful magnification’ of a 10” telescope is 500X.

But that couldn’t be further from the truth. Higher clarity you get with longer focal point, not bigger apertures. So, in my experience, if you really want to know the real useful magnification you get when using a certain telescope, you just divide the focal length with 5. For a scope with a 1000 mm focal length, you get decent magnification at 200X. But my experience is not a measuring standard; you can use these rules just for your better understanding of what to expect.

Use a Barlow lens

Sometimes the use of additional optics can give you a different experience in stargazing. The problem comes with the price of those Barlow lenses. The higher quality Barlow lens can cost the same as a medium-range eyepiece, so it’s better to buy a second medium-range eyepiece than a high-end eyepiece with a high-quality Barlow lens as a secondary eyepiece.

Barlow lens is good to have them at the beginning, while you are collecting better and different eyepieces. Beginners with smaller telescopes, let’s say smaller apertures than 6” can have their fair share of play with Barlow lenses, but as soon as you start to buy more expensive scopes and eyepieces, Barlow lens becomes obsolete.

I don’t recommend the use of Barlow lens with bigger, better telescopes, for example, 12”+ and higher quality eyepieces. And when you use low quality/cheap eyepieces, then you just buy 2 or 3 eyepieces instead of the Barlow lens.

Pick the right eye relief and exit pupil

Eye relief is the distance you can place your eye from the eyepiece while having the full image in focus. With that said, most of the people who use glasses tend to obtain eyepieces with longer eye relief. I don’t recommend you to use your glasses while stargazing, because you’ll get some external light reflections, possible lens distortions because of lens misalignment and possible chromatic aberration on the edges. Just remove your glasses and use the focuser to adjust the image.

The exit pupil is important when you observe the faintest deep-sky objects. You need all the gathered light to be projected onto your retina through your widely dilated pupils. 

Apparent Field of View and True Field of View

A large apparent field of view (AFOV) is what you are looking for in a high-quality eyepiece. The larger the number, the larger part of the sky you can see. Eyepieces with a narrow apparent field of view feel claustrophobic, and uncomfortable for viewing, feels like looking through a keyhole.

  • Eyepieces with 40° – 50° apparent field of view are considered to have a narrow field of view; these are not recommended at all except for the longer focal lengths.
  • Eyepieces with 50° – 65° apparent field of view are midrange eyepieces. Cheapest eyepieces come up till 65° of AFOV.
  • Eyepieces with 65° – 85° apparent field of view are considered to be wide-angle eyepieces. These are probably the best price for value and this is where the price starts to climb.
  • Eyepieces with 85° – 95° apparent field of view are considered to have an ultra-wide apparent field of view. When you get the budget to by one of these, just do it.
  • Eyepieces with 95°+ apparent field of view are exceptional eyepieces with an extreme ultra-wide apparent field of view and, of course, the most expensive ones.

For example, a 40 mm eyepiece may have a 40° apparent field of view, while a 30 mm may have a 50° apparent field of view. The true field of both of those eyepieces (part on the sky) are identical, just the image on the 30 mm would look a bit zoomed in. Let’s say a third eyepiece with the same true field of view would be a 20 mm with around 80° apparent field of view eyepiece. Of course, the magnification would be different between those three, but you’ll observe the same part of the sky.

The true field of view is measuring how much of the sky you are looking clearly (angular size). Realistically you can have between 0.2° and 2° with most of the telescopes. Bear in mind that the Moon is 0.5° in angular size. With high-end equipment, you can go below 0.2° and higher than 2° in angular size.

 

How many eyepieces do you need?

As I’ve already mentioned many times, no matter what kind of a telescope you have from 3” to 16”+ your first eyepieces should be one between 9 – 13 mm and one between 20 – 24 mm with as wide apparent field of view as possible. That means you can purchase the 40+ mm eyepiece with 50°+ of apparent field of view if possible. 

  • With 40 mm eyepiece, you can observe the largest deep-sky objects like the Andromeda galaxy, the Pleiades, Rosette Nebula, Orion Nebula, etc. 
  • After this you can go sub 7 mm territory, where decent eyepieces are $200+, you just can’t go cheap with these focal lengths. Or maybe you can obtain the planetary variants with narrow exit pupil, only for observing the planets and the Moon.
  • Some objects look better at low magnification, some at medium magnification, some at high magnification, and some at very high magnification. It is as simple as that. 

Not everything in the sky benefits from high magnification. Some deep-sky objects are 5 times bigger than the Moon in angular size.

Also, atmospheric conditions and elevation from the horizon can limit how much magnification you can use on a given night.

Best telescope eyepieces

1. SVBONY Telescope Lens 62° Aspheric Eyepiece for 1.25 inch (4 mm; 10mm; 23 mm)

These eyepieces are highly recommended, especially the 10 mm and the 23 mm. 

At a very low price, they give you quite a wide apparent field of view and good image quality comparable to eyepieces that are 15 times more expensive. 

Build quality is not bad at all, better than what one can expect at this price. 

The 23 mm eyepiece is the largest and 10 mm one is actually smaller than 4mm one.

4 mm eyepiece is where the image breaks down, still better than Plossls and Kellners. My recommendation is if you want that high magnification, you should go with high-end eyepieces.

Because of their small size, higher thermal conductivity prevents fogging at low temperatures.

Check the price of SVBONY Telescope Lens 62° Aspheric Eyepiece here

What we liked

  • Very, very cheap
  • Remarkable 62° apparent field of view for this price
  • Crisp and sharp image from edge to edge
  • By far better viewing than a bit higher priced Plossls and Kellners 
  • Easy for maintenance

What we didn’t like

  • You just can’t find negative thing at this unbeatable price

Apparent Field of View: 62 degrees
Focal Length: 10 mm and 23 mm
Barrel Size: 1.25″
Eye Relief: 9 mm

2. Gosky Plossl 40 mm Telescope Eyepiece - 1.25inch

This is probably the worst eyepiece I can recommend. 

The only reason it’s in this list because of its price and a long focal point

At least you’ll have one budget eyepiece that will give you a larger part of the sky at low magnification.

The optics are awful; there is a very low contrast because of the lack of coating. 

But again, the price overweighs it. Somewhat noticeable image distortion and chromatic aberration at the outer edges. 

With this eyepiece, you’ll experience how worst eyepieces look like, so please stay away from plossls at shorter focal points.

Check the price of Gosky Plossl 40 mm Telescope Eyepiece 1.25inch here

What we liked

  • Nice and cheap for beginners
  • Fairly good image at the center
  • Low magnification at low price

What we didn’t like

  • Long eye relief. At the position where the image is in focus, you don’t get the whole field of view
  • Narrow apparent field of view at about 40°, despite the claimed 52° apparent field of view

Apparent Field of View: 40 degrees (52 declared)
Focal Length: 40 mm
Barrel Size: 1.25″
Eye Relief: 28 mm

3. Meade Instruments 10 mm, 100 Degree MWA 1.25-Inch

I had much better expectations when I read the specs of this eyepiece. 

But this is still a bargain at this price point

Because of its awkward, long eye relief, the view looks narrower with an apparent field of view at 85° or 90°. 

For more experienced stargazers, there is noticeable image distortion on the outer edges where smearing is the most annoying.

With all mentioned bad characteristics, using this eyepiece for observing deep-sky objects at a mega-wide angle will give you exceptional view with high contrast.

This will probably be your first high-end eyepiece that I’m sure you’ll enjoy even brag about it.

Check the price of Meade Instruments 10 mm, 100 Degree MWA 1.25-Inch here

What we liked

  • Very cheap for high-end eyepieces
  • Nice, sharp image when you center your eye at the eyepiece
  • Quite large apparent field of view

What we didn’t like

  • Eye relief is too far and may feel awkward for seasoned stargazers

Apparent Field of View: 100 degrees
Focal Length: 10 mm
Barrel Size: 1.25″
Eye Relief: 19 mm

4. Explore Scientific 40 mm - 68° Field of View Eyepiece

This is what will get you to marveling at the night sky as none of the other eyepieces can. 

With this one, at first glance, you’ll probably say ‘Wow’ right after you get the first image in focus. 

Later you can point at the largest objects in the sky to observe them in their natural habitat. 

For example Andromeda and its neighboring galaxies, Bode and Cigar galaxy, the Pleiades will look like diamonds in the sky. 

Most of the deep-sky objects will be sprinkled by hundreds of stars to enrich your view and bring you closer to the stars as never before.

This is very heavy eyepiece; you’ll probably need to put counterbalance on your scope.

Check the price of Explore Scientific 40 mm 68° Field of View Eyepiece here

What we liked

  • On par with the highest-end 40 mm eyepieces at half the price
  • One of the best 40 mm eyepieces at this price point
  • Great eyepiece for any size of scope, from smallest to the largest ones
  • Large apparent field of view for this focal length
  • Nice build quality
  • Great eye relief that feels natural

What we didn’t like

  • It is pricey, but well worth the money
  • Very heavy eyepiece

Apparent Field of View: 68 degrees
Focal Length: 40 mm
Barrel Size: 2″
Eye Relief: 31 mm

5. Tele Vue 13 mm Ethos 2" / 1.25" Eyepiece with 100 Degree Field of View

This is one of the best eyepieces out there. 

Superior optics will give you a perfect image edge to edge and possibly the best contrast for those deep-sky objects. 

Perfect eye relief is there to help you enjoy the whole ultra-wide view of the skies.

When you get the budget to purchase one, I highly recommend it if you own a larger Dobsonian telescope. 

If you use it with smaller refractors, you’ll still have an exceptional image, but it’s a bit overkill.

Build quality is exceptional; all of the components are well produced. This is a big eyepiece, so you might have to put counterbalance on your scope in order to keep it leveled.

Check the price of 5. Tele Vue 13 mm Ethos 2″ / 1.25″ Eyepiece here

What we liked

  • The king of eyepieces
  • Extremely large apparent field of view at 100°
  • Superior quality optics
  • Sharp image from edge to edge
  • Very high contrast
  • Well built

What we didn’t like

  • High price
  • Large and heavy case
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