Upgrade your lenses for mesmerizing views of our galaxy. Check out these high-quality Barlow lenses that will get you closer to the stars at any price point.
Since the dawn of time, man has been captivated by the stars, planets, and galaxies light-years away. It’s only natural that over the millennia we’ve developed different optical systems that allow us a better peek into the night sky. While you might think you’re limited by the telescope you already own, there’s another, cheaper way to achieve fascinating images of the stars around us.
A handy tool for at-home astronomers, the Barlow lens was designed specifically to enhance the views of the celestial bodies you can expect to see through a telescope. However, early on humans realized that simply increasing magnification power does not yield more insight into the above skies. The field of optics has had to understand and overcome wavelengths, focal lengths, apertures (terms we’ll explore in this article) to design lenses that produce quality images. Many of these factors will also help you determine whether you should invest in an achromatic or apochromatic lens to correct issues and increase your magnification.
Why You Need A Barlow Lens
Whether you’re a hobbyist stargazer or practiced astrophotographer, your craft can benefit from the right Barlow lens. These lenses are designed so that you can easily thread, or screw, the Barlows lens directly into your eyepiece so that it is between the eyepiece and the telescope’s objective lens. The added lenses will double your magnification power without losing image quality because of the unique design. It’s also the cheapest way to increase your eyepiece collection. For example, a 20mm eyepiece with a Barlow lens will now give the same results as a 10mm eyepiece. Essentially, it is the only way to see craters on the moon or a close image of Mars with limited – or in the case of these apochromatic lenses – no distortions.
Just like when buying a telescope, you should consider your needs and budget before purchasing an apochromatic Barlow lens. The market ranges from about $20 to several hundred dollar lenses. A common myth on the internet is that Barlow lenses degrade image quality. A Barlow lens can indeed lengthen the focal length, which will help with magnification, but can have the effect of making images appear distorted, depending on the image you are trying to capture. A high-quality telescope with high-capacity light gathering will also help to correct distortions and create contrast. Although the sage advice, you get what you pay for, holds here, your power of magnification on a Barlow lens should complement the quality of your telescope. A high magnification Barlow lens will still be blurry if your telescope has a smaller objective lens or low-quality optical system.
As you can see, there are a ton of factors for achieving the images you want of our galaxy. Before diving into our recommended brands for every price point, let’s first dig into lens quality and key terms so that you can make an informed decision.
How Lenses Work
The quality of a lens can make or break the overall optical system of your observational tool. Science has made great strides in figuring out how to produce bright and clear images. One of the best improvements for cameras, binoculars, telescopes, and other optical tools has been the creation of the apochromatic lens. We’ll talk more about why these lenses are more than just a splurge, but rather a necessity for even a beginner astrophile. But first, it’s important to understand how lenses and color wavelengths work.
Not to sound too much like the Matrix, but the colors that we see are not inherent to objects. Color is produced by wavelengths that come from the white light of the sun. According to NASA, each color has a different wavelength, and once that specific wavelength is refracted off of an object and perceived by the lens of our eye, we can see the color. Not quite as magical as Dorothy waking up in Oz, but pretty close.
However, lenses, including our eyes, have some serious disadvantages when it comes to perceiving color. Because of the different wavelengths, when light passes through a prism, a.k.a. your eyes, Nikone camera, telescope, they don’t all meet up at the same time or focal point. Think of your family members who all have different definitions of what being on time means and the incoordination that causes! In the optics world, this discord is known as dispersion. It’s also responsible for some real beauty in the world, like rainbows.
Achromatic v. Apochromatic Lenses
Thanks to the hard work of scientists, like Peter Barlow (yes, of Barlow lens fame), we now have lenses that help to correct light dispersion and chromatic, or color, aberrations it causes. As a result, you’ll notice two types of lenses on the market – achromatic and apochromatic. Achromatic lenses involve two glass lenses, one converging and one diverging, that are separated to the tiniest minute by some liquid or gas. The combination of lenses is also sometimes referred to as glass elements. You can tell how many pieces of glass a lens has by how many glass elements are listed. For example, two lens elements mean there are two pieces of glass acting as a lens.
This two-glass element system helps two of the three main color wavelengths sync up at a common focal point. According to Zeiss, a leading manufacturer of optical systems, a larger aperture, or light-gathering capacity, will help an achromatic lens to correct more of the color wavelengths and produce a better image. However, this means an achromatic lens in a cheap optical system is still going to leave you with distortions.
Apochromatic lenses are the premium deluxe in the optical world. These lenses are the gold standard because they tame all three of the primary color wavelengths. In a process known as apochromatic refraction, three lenses work together to focus the wavelengths to a common focal point. This three-element system will also give you a higher contrast in your images as there is less light scatter that occurs as you view an image. Unfortunately, since apochromatic lenses only work on the three primary color wavelengths, this means the violet wavelength can still cause somewhat of a nuisance. You can expect there will occasionally be a purple halo effect due to that pesky wavelength. APO lenses are the finest of optical systems, and a true APO lens will come with a price tag that shows its elite class. If there’s one this to splurge on though, it’s this.
Without an apochromatic lens, there will be chromatic aberrations that occur. Different chromatic aberrations can lead to color-fringing (picture a photo with a faint halo of green or red around an object), blurriness (think astigmatism), and lack of depth perception. For viewing the night sky, it is especially critical to correct for these chromatic aberrations because you’re already combating factors such as air turbulence and light pollution.
Although apochromatic lenses are top of the line, they’re going to cost you a pretty penny. Depending on your telescope and your level of interest in high-quality images, it might be worth just sticking with the cheaper achromatic lens. Either way, we’ve brought you the top three Barlow lenses on the market that can meet you halfway at any budget and ensure you have unlimited views of the night’s sky.
SVBONY 2X Barlow Lens 1.25 inch
The SVBONY 2x Barlow Lens is one of the most budget-friendly on the market, coming in at $16.99. Amazon offers three versions for purchase, and it’s important to note which one you’re ordering. There is a 2x, 3x, and 5x magnification eyepiece. Most home astronomers agree that a 2x Barlow lens is the highest you should go in magnification with a beginner or mid-range telescope. As previously mentioned, higher magnifications with a smaller aperture telescope are not going to shorten the focal length. The image will appear closer but will be blurry and distorted.
It’s also important to note that this Barlow lens uses achromatic lenses rather than apochromatic. As a reminder, the achromatic lens will only correct two wavelengths, so despite the assurances from their Amazon page that their achromatic lens is “advanced” there is likely still some color-fringing that will occur. Several Amazon reviewers confirm that while this product is great for the price, there will be distortions and the product is a bit flimsy.
A bit of saving grace is their lens is multi-coated and the housing is blackened. This combination allows in more light, which will help with image quality.
Our take – This Barlow lens is great to use for kids and novices practicing backyard astronomy.
GSO 1.25″ 2.5x Apochromatic Barlow Lens
The GSO 1.25” 2.5x Apochromatic Barlow Lens is one of the best and unique in the market. GSO’s (Guan Sheng Optical) Barlow lens is a big step up in price, but also image quality. This Barlow lens is full-on apochromatic, meaning those color wavelengths will be kept in check. This lens also packs a powerful punch with 2.5x magnification. The magnification does let the GSO stand out as different in the Barlow lens market, where most are either 2x or 3x magnification. Again, you’ll want to make sure your telescope can handle the level of magnification that you are looking to produce with your Barlow lens. According to homeschooling experts at, Home Science Tools, “a basic rule of thumb is the maximum magnification is 2.4 times the aperture diameter in mm or 60 times the aperture diameter in inches.”
Similar to the SVBONY, the edges and the barrel of the GSO are also blackened to allow for ultimate light-gathering capacity. GSO also mentions its 23 mm aperture. However, several reviewers of the product commented that this Barlow lens might be closer to 2x magnification rather than 2.5. This could be difficult to prove, and might not make much of a difference to novice astronomers.
Our take – This Barlow lens is great to use for emerging and longtime astronomy hobbyists
Astromania 1.25″ 2X TeleXtender Barlow Lens
The Astromania 1.25” 2x TeleXtender Barlow lens is another great option for stargazers looking to see the details of celestial bodies. Another apochromatic lens – meaning a three lens-element design – this Barlow lens will give you crisp, clear images. The 2x magnification power and the brilliant optical system will pair well with any 1.25” barrel telescope. Their website confirms their Barlow lens is multi-layered and multi-coated and boasts that their APO lens will yield high-contrast images. Altogether, this Barlow lens is excellent for taking pictures of planets, stars, and galaxies.
The price tag of this Barlow lens will also buy you comfort. This product maintains a good eye relief so that you can observe for hours on end. Astromania is also great for astrophotographers and allows you to connect your DSLR camera via the Barlow’s lens’ compression ring.
The only downside to this Barlow lens, aside from cost if you’re watching your budget, is the discrepancy in their website’s marketing materials. The market materials claim that this product has four lenses in some places, but the name describes the Barlow lens as being a three-element lens. While four-element Barlow lenses exist, this product does seem to only have three. A three-element APO lens is plenty for your stargazing needs, but it is worth noting this discrepancy.
Our take – This Barlow lens is great to use for committed astrophotographers.
Many factors and calculations go into astronomy, which is part of the allure that attracts many amateur stargazers. Understanding lenses and their interactions are the first big step as you get started in exploring the night sky. Once you know your telescope and the images you’re trying to capture, it’s easy to select the Barlow lens that best fits your needs. A Barlow lens is a key utensil that any home-astronomer should have in their tool kit, and at these prices, there’s no excuse not to get your hands on one.