Best Telescope Eyepieces: Leveling Up Your Astronomy Game

Nothing is more exciting than buying a scope and taking it outside for the first time. The majority of scopes now come supplied with two or three eyepieces that will give you the chance to start exploring the heavens above – but let’s be honest, the chances are those eyepieces aren’t the greatest. They might be fine for looking at large, bright objects that don’t require a lot of magnification, but when it comes to high-powered views of globulars and galaxies, the fact is, those eyepieces just won’t do. So what’s the alternative? What are the best telescope eyepieces you can buy?

The good news is that there’s a wide range to choose from and there’s sure to be one to suit your budget. To save you time (and potentially money), we’ve looked at the many of the best telescope eyepieces available and picked the cream of the crop to help you make the most of your scope.

(Before we begin, please note that product pricing, price categories and availability are accurate as of the date of this post, but are subject to change. This post represents the author’s opinion, based on research and experience, of the “best” or “top” products in this category; the opinions of others may vary. If you have other questions, let us know through our ‘contact us’ page and we will try to get you more information.)

Image Credit: Richard Bartlett / TelescopeGuide.org

Part 1 | Before You Buy: What You Need to Know

Before we start to review our recommendations, let’s have a brief overview of the types of eyepieces available. (Incidentally, the eyepieces that come with new telescopes are typically Plössls or Kellners.)

• Plössl – Designed by Georg Simon Plössl in the mid-19th century,  these are the most common eyepieces on the market and consist of two pairs of back-to-back lenses. They’re inexpensive to produce and can have a wide field of view, but can also be prone to distortion. 

• Kellner – Typically cheaper than a Plössl, Kellner eyepieces have a smaller field of view and shorter eye relief, making them a little more uncomfortable on the eye. They consist of three lenses and can produce sharp views with little color defects or distortion.  

• Orthoscopic – Also known as Abbe eyepieces, these utilize a compound lens that consists of three individual lenses. Like the Kellner design, orthoscopic eyepieces produce sharp views but they also offer greater contrast, longer eye relief and are almost completely free of distortion. The catch? They generally have a smaller field of view and are more expensive. 

The Nagler Revolution

These three were the common standard types of eyepiece until 1979, when Albert Nagler produced a new type of eyepiece consisting of up to eight lenses. Not only can Nagler eyepieces produce distortion-free images, but they also have an 80 degree field of view – nearly double that of a standard eyepiece.

The design was further enhanced by TeleVue with their Ethos range of eyepieces, which are capable of producing a field of view spanning 110 degrees.

The problem with Nagler and Ethos eyepieces is that the extra lenses add to both the cost and the weight, with some weighing more than a pound and potentially costing more than the telescope itself. However, while being something of a luxury, Nagler and Ethos eyepieces are considered to be the best telescope eyepieces on the market, but fortunately, if it’s a wide field of view you want, there are less expensive options available.

Image Credit: Richard Bartlett / TelescopeGuide.org

One last thing; if you’re on a budget and can’t afford a range of eyepieces, consider buying a zoom eyepiece instead. A traditional eyepiece can only produce one magnification, but a zoom eyepiece will provide a range, allowing you to observe your target without having to switch eyepieces. 

The problem here is that the quality is not usually as good as a regular eyepiece and the field of view is frequently smaller. However, they can be a very convenient option if you’re traveling and don’t want to carry a case full of eyepieces everywhere! 

What to Look For in an Eyepiece

If you’re shopping around for the best telescope eyepieces, there are a few considerations you should always keep in mind:

Focal Length

This is the distance light must travel between entering and exiting the eyepiece. The magnification of an eyepiece can vary as it depends on the focal length of both the eyepiece and the telescope. (You can typically find the focal length of your telescope printed on a label affixed to the telescope tube.)

To calculate the magnification, you need to divide the focal length of the telescope by the focal length of the eyepiece. For example, if your telescope has a focal length of 1000mm and your eyepiece has a focal length of 10mm, then it will produce a magnification of 100x. If you were to use the same eyepiece in a telescope with a focal length of 650mm, you’d have a magnification of 65x.

If you want a low magnification, you’ll need an eyepiece with a long focal length (eg, 20mm.) Conversely, if you want a high magnification you’ll need an eyepiece with a short focal length (eg, 6mm.)

Image Credit: Richard Bartlett / TelescopeGuide.org

What is the Apparent Field of View of an Eyepiece?

The Apparent Field of View and True Field of View of an eyepiece are two numbers that have similar meanings. Both are important, but in slightly different ways.

The Apparent Field of View (AFoV) is the viewing angle produced by the eyepiece. To clarify, the human eye has a viewing angle of about 160 degrees. In other words, if you were to close one eye and look straight ahead, you’d be able to see for about 80 degrees on either side of the center.

Many Plössl eyepieces have an AFoV of about 40 or 50 degrees – less than a third of the human eye – while an Ultra Wide or Ethos eyepiece can produce an AFoV of 100 or 110 degrees. The AFoV of an eyepiece remains the same, no matter which telescope you use it with, and is typically listed as one of the specifications of the eyepiece.

What is the True Field of View of an Eyepiece?

The True Field of View (TFoV) is the amount of sky you’ll be able to see through the eyepiece. For example, the Moon covers roughly half a degree in the sky, so if you wanted to see its entire disc in the eyepiece, you’d need a low-powered eyepiece with a TFoV of half a degree (30 arcseconds) or more.

The True Field of View of an eyepiece will vary, depending on the scope’s focal length and the resulting magnification. To calculate the TFoV, you first need to calculate the magnification by dividing the focal length of the scope by the focal length of the eyepiece. You’ll then need to divide the AFoV of the eyepiece by the magnification.

For example, the Celestron NexStar 130SLT telescope has a focal length of 650mm. When using a regular 25mm eyepiece with an actual field of view of 50 degrees, you’d get the following results:

• A magnification of 26x (Telescope focal length divided by eyepiece focal length: 650 / 25 = 26)
• A true field of view of 1.9 degrees (Eyepiece AFoV divided by the magnification: 50 / 26 = 1.9)

What Are the Two Most Common Eyepiece Barrel Sizes?

Depending on the make and model of your telescope, you’ll find the focuser – where you insert the eyepiece and then focus the view – will either accept eyepieces with a barrel 1.25” wide or 2” wide. (Don’t buy a telescope that accepts anything smaller. A reputable manufacturer will only use one of those two sizes nowadays.)

Of the two, 1.25” barrels are more common, as they tend to be built for the mass market, whereas 2” barrels are typically designed for higher-end, more expensive telescopes.

Wider barrels allow for a wider field of view, making it easier to observe larger targets. For that reason, 2” barrels can have a longer focal length, but are a little limited when it comes to shorter focal lengths. More specifically, they can often have focal lengths ranging from between 15mm and 40mm.

On the flip side, 1.25” barrel eyepieces can perform better with shorter focal lengths but they’re a little restricted with longer focal lengths. The focal lengths of 1.25” eyepieces can typically range from 3mm or 4mm to about 25mm.    

The good news is that you can buy adapters that will allow you to swap from one to another – and some eyepieces have barrels you switch to fit your focuser.  

What is Eye Relief?

You’ll hear this term a lot when it comes to binoculars too. The eye relief of an eyepiece (or binocular!) is the distance your eye can be from the eyepiece and still see the whole field of view.

This is important if you wear glasses, as you obviously won’t be able press your glasses up  to the eyepiece but will need to be a little distance from it instead. The greater the eye relief, the further you can be from the eyepiece and the more comfortable the observing experience.  

Realistically, you shouldn’t settle for anything less than 15mm of eye relief, which is true of all of the eyepieces discussed here.

Magnification

As explained earlier, the magnification of the eyepiece is determined by its focal length and the focal length of the telescope you’re observing with. An eyepiece with a 10mm focal length will give you a magnification of 100x in a telescope with a focal length of 1000mm and a magnification of 70x in a telescope with a focal length of 700mm.

It’s a good idea to know the focal length of your telescope when you’re shopping around for an eyepiece, as it will give you an idea of the magnification you’ll get as a result. The simple rule is this: eyepieces with a long focal length will give you a lower magnification while eyepieces with a short focal length will give you a higher magnification.

For this reason, it’s advisable to own a selection of eyepieces to ensure you have a range of magnifications available as you observe. That way you’ll have the most suitable eyepiece available for both your equipment and the object you’re observing.

Part 2 | Our Top Picks for the Best Telescope Eyepieces

Ask a range of amateur astronomers what the best telescope eyepiece is, and you’ll probably get a range of answers. A lot will depend upon your budget, the capabilities of your telescope and what objects you intend to use it for.

Different Targets Require Different Magnifications

For example, open star clusters can be comparatively large and bright and are best seen at a low magnification. In that case, an eyepiece with a long focal length would be the best option as they produce a lower magnification view. 

Conversely, smaller targets – such as planetary nebulae and the planets themselves – require a higher magnification, so you’ll need an eyepiece with a short focal length to observe those. (You’ll also ideally need a larger scope with a longer focal length to allow you to gather as much light as possible and produce a higher magnification view.)

As for the best eyepiece to observe the Moon – do you want to admire the beauty in seeing the whole of the Moon or do you want a stunning close-up view that makes you feel as though you’re skimming over the surface?

Again, to see the whole of the Moon you’ll need an eyepiece with a long focal length for a low magnification, and to see a close-up view, you’ll need an eyepiece with a short focal length for a high magnification.

Other Factors to Consider Before You Buy

Who makes the best telescope eyepieces? Arguably, that would be TeleVue, as they’re known for consistently producing high-quality, premium eyepieces – but they also come at a premium price.

If your budget is a little more restrictive, Celestron produces a wide range of eyepieces that provide a good combination of economy and quality. Another company, SVBONY, has risen to prominence over the past few years and is now producing a range of eyepieces and accessories at very reasonable prices.

Lastly, it used to be the case that wide field eyepieces (with a wide actual field of view) were expensive, but that’s not necessarily the case anymore. It’s now possible to buy a decent quality eyepiece, with an actual field of view of 50 degrees or more, for a reasonable price, and all our choices reflect this. 

With all this in mind, you should be able to find the right eyepiece to suit your needs and your budget in the list below.

1. SVBONY Plossl Eyepieces – Our Pick of the Best Budget Eyepieces

As with almost everything, if you want premium quality, you typically need to pay a premium price for it. However, that doesn’t mean you can’t buy some decent kit for a fair price, and this is where SVBONY come in. A Chinese company founded in 2009, they specialize in producing astronomical accessories for a reasonable price.

For example, the company produces a limited range of Wide Angle Aspheric Plössl eyepieces. The eyepieces each have an actual field of view of 62 degrees and are available in focal lengths of 4mm, 10mm and 23mm. These are incredibly reasonably priced; you can buy all three for less than the price of a single eyepiece from almost any other manufacturer. 

Image Credit: Richard Bartlett / TelescopeGuide.org

The downside? They’re only available with 1.25” barrels, so if you have a 2” focuser, you’ll either need an adapter or you’ll need to look elsewhere.

2. TeleVue Ethos – Our Pick of the Best Premium Eyepieces

Without a doubt, when it comes to premium eyepieces, the king of the jungle is still TeleVue. The company’s Ethos and Ethos SX eyepieces are the cream of the crop, with the Ethos boasting an actual field of view of 100 degrees and the SX going one step beyond with 110 degrees. As you might expect, both are capable of producing sharper, higher contrast views than their less expensive peers.

Both ranges are available in a variety of focal lengths, with the 21mm Ethos 2” eyepiece and the 13mm Ethos 1.25”/2” eyepiece proving to be the most popular. If you have the money to treat yourself to one of these gems, bear in mind that 1.25” barrels are only available with a focal length of 13mm or less, whereas observers with a 2” focuser should have no problem using the entire range.

(The focal lengths of the Ethos range from 6mm to 21mm while the Ethos SX is available with focal lengths of either 3.7mm or 4.7mm.)

The other problem is their weight; these are not lightweight eyepieces, either in terms of the impact on your wallet or your telescope. The lightest of the bunch, the Ethos 8mm, weighs just under a pound, while at the other end of the scale, the 21mm Ethos eyepiece weighs two and a quarter pounds.

These eyepieces are therefore not recommended for a small refractor, for example, as the additional weight of the eyepiece will pull the optical tube of the telescope down!

3. Apertura Super Wide Angle – Our Pick of the Best Long Focal Length Eyepieces

If you’re looking for a stunning, low-power view of a large star cluster (such as the Pleiades, for example) you’ll need an eyepiece with a long focal length. You can probably consider any eyepiece with a focal length greater than 20mm to be long, but there’s one option that’s nearly double that.

The Apertura Super Wide Angle has a focal length of 38mm and an actual field of view of 70 degrees, giving you both a low power and a wide viewing angle to enjoy all the larger deep sky objects that would otherwise struggle to fit within your field of view. For example, using this eyepiece with a 1000mm focal length scope will produce a wonderfully low 26x.

However, if you have a 1.25” focuser, you’re out of luck as this particular eyepiece is only available with a 2” barrel. That being the case, consider the 25mm Celestron X-Cel LX for about the same price, but be aware that besides having a shorter focal length, its actual field of view is 10 degrees less too.

4. Celestron X-Cel LX – Our Pick of the Best Short Focal Length Eyepieces

The eyepiece with the shortest focal length in our selection is the 2.3mm Celestron X-Cel LX. Not only is it reasonably priced, but it also has an actual field of view of 60 degrees, giving it the ability to provide some wonderful, close-up views of distant galaxies, planetary nebulae and, of course, the planets themselves. 

(A 1000mm focal length telescope would produce a magnification of 434x – but make sure your scope has the aperture to handle it!)

The 2.3mm X-Cel LX is only available with a 1.25” barrel and the next best option for anyone with a 2” focuser is the 3.7mm TeleVue Ethos SX. While it has a slightly longer focal length, its actual field of view is a staggering 110 degrees – but it also comes with a very large price tag.

Unfortunately, there are no 2” eyepieces with a focal length of less than 10mm for about the same price as the 2.3mm Celestron X-Cel LX, which might be one good reason by itself to choose a scope with a 1.25” focuser!

5. TeleVue Ethos SX – Our Pick of the Best Wide Field Eyepieces

It could be argued that each of the best telescope eyepieces highlighted here is wide-field, but there are two that stand out from the rest. For starters, the TeleVue Ethos SX eyepieces (both 3.7mm and 4.7mm models) have an actual field of view of 110 degrees and will fit 1.25” and 2” focusers. But, once again, the price might be a little off-putting.

The less expensive alternative is the Omegon Panorama II range of eyepieces. Choose between focal lengths of 5mm (1.25” barrel), 10mm (1.25” barrel) or 15mm (2” barrel), with each providing a 100 degree actual field of view. 

6. Celestron Zoom Eyepiece – Our Pick of the Best Zoom Eyepieces

Finally, we come to zoom eyepieces. These are a good option if you’re on a budget or don’t want to carry a number of eyepieces around. The good news is that they’re not too expensive, but our selection doesn’t include any eyepieces with a 2” barrel. You’ll also find the actual field of view will change, depending on which focal length you currently have selected.

Image Credit: Richard Bartlett / TelescopeGuide.org

The one zoom eyepiece that’s a consistent favorite with experienced observers is the Celestron Zoom 8mm-24mm. You can choose any focal length between 8mm and 24mm and it costs roughly the same as other individual eyepieces with similar focal lengths. The actual field of view will vary from 40 to 60 degrees.

You can save even more money by choosing one of three zoom eyepieces from SVBONY. The options are 7mm to 21mm (actual field of view 40-57 degrees),  8mm to 24mm (38-56 degrees) and 10mm to 30mm (33-51 degrees).

Final Thoughts on the Best Telescope Eyepieces

A good telescope is only as good as the best telescope eyepieces you use with it. Buy a cheap eyepiece from an unknown manufacturer and you run the risk of ruining the outstanding views your scope provides. By investing a little more money in a solid eyepiece accessory, you’ll not only improve the view, but also your enjoyment of the hobby too. 

Feature Image Credit: Quils / iStock