It’s Time to Talk About the Explore Scientific 20mm 68 Degree Series Argon-Purged Waterproof Eyepiece
When you spend significant time observing the night sky, the right eyepiece can transform your experience from good to truly breathtaking. For years, I’ve relied on various optics for my astronomical pursuits, but I was continually encountering frustrating issues with internal fogging and dust ingress. This is precisely what led me to seek out the Explore Scientific 20mm 68 Degree Series Argon-Purged Waterproof Eyepiece. The promise of superior clarity and freedom from environmental contaminants made this an intriguing prospect.
My initial impression upon unboxing this optic was one of solid craftsmanship. The unit feels substantial in hand, with a satisfying weight that speaks to its robust construction. It immediately conveyed a sense of reliability, a stark contrast to some of the lighter, more plasticky eyepieces I’ve used in the past.
While I considered other brands, the specific combination of an argon-purged, waterproof design with a 68-degree apparent field of view made this Explore Scientific model stand out. My first reaction was a quiet sense of anticipation, a hope that this eyepiece would finally solve the persistent annoyances that had been plaguing my observing sessions. It felt like a significant upgrade was finally within reach.
Real-World Testing: Putting Explore Scientific 20mm 68 Degree Series Argon-Purged Waterproof Eyepiece to the Test
First Use Experience
I first put this eyepiece through its paces during a particularly humid night in my backyard observatory. The air was thick with moisture, conditions that typically wreak havoc on optical equipment. Despite the challenging atmospheric conditions, the Explore Scientific 20mm 68 Degree Series Argon-Purged Waterproof Eyepiece performed admirably, delivering crisp views without any hint of internal fogging.
Its usability was immediately apparent; the 15.3mm of eye relief made it comfortable to use, even for extended periods, without the need to press my eye uncomfortably close to the lens. This was a welcome change from narrower eyepieces where maintaining a consistent viewing position could be a chore.
The only minor surprise was how much clearer the edge of the field appeared compared to my older eyepieces, even though the 68-degree field was already quite wide. This particular optic revealed details I hadn’t previously noticed at the periphery of my view, enhancing the overall immersive experience.
Extended Use & Reliability
After several months of regular use, through dew-laden mornings and even a light drizzle during a meteor shower, this eyepiece continues to impress. It has become my go-to for general viewing, offering consistently sharp images across a variety of celestial objects. The argon purging has proven its worth, keeping the internal optical surfaces pristine and free from any moisture or debris.
There are absolutely no signs of wear and tear; the rubber eyeguard is still supple, and the barrel shows no scuffs despite being inserted and removed from my telescope focuser numerous times. Its durability is evident in its consistent performance, resisting any degradation in image quality over time.
Maintenance has been nonexistent, which is precisely what you want from a high-quality, sealed optic. A quick wipe of the external lenses with a microfiber cloth is all that’s ever needed, making it incredibly low-maintenance. Compared to budget eyepieces that degrade quickly, this unit feels built to last for many years of dedicated stargazing.
Breaking Down the Features of Explore Scientific 20mm 68 Degree Series Argon-Purged Waterproof Eyepiece
Specifications
The Explore Scientific 20mm 68 Degree Series Argon-Purged Waterproof Eyepiece boasts a focal length of 20mm, providing a moderate magnification suitable for a wide range of celestial targets, from nebulae to star clusters. Its apparent field of view is a generous 68 degrees, offering an expansive vista of the night sky that pulls you into the scene. The eyepiece measures 69.6mm in length and 50.3mm in width, with a substantial weight of 8.7oz (247g), indicative of its solid construction.
It features a standard 1.25″ barrel size, making it compatible with the vast majority of astronomical telescopes. The eye relief of 15.3mm is a key specification, ensuring comfortable viewing for observers with or without eyeglasses. Furthermore, the field stop diameter of 22.8mm contributes to the immersive wide-field experience, minimizing the distracting “kidney bean” effect.
The argon-purged and waterproof nature of this eyepiece is a critical feature, protecting the internal optical elements from moisture, dust, and fungus. This means you can observe in challenging conditions without worrying about internal contamination or fogging, ensuring consistent performance over time. The optical design employs advanced computer design, combinations of low dispersion and high refractive index optical glasses, and durable multilayer deposition coatings to maximize light transmission and minimize optical aberrations.
Performance & Functionality
In its primary role as an astronomical eyepiece, this Explore Scientific model excels. The 20mm focal length strikes a pleasing balance, offering enough magnification to resolve details on planets and brighter deep-sky objects, while its wide 68-degree field of view makes sweeping through star fields and locating fainter targets an absolute joy. Images are sharp and well-defined, particularly in the central portion of the view.
A significant strength is the flat field performance; edge-of-field aberrations are remarkably well-controlled for an eyepiece of this focal length and field of view. This means stars remain sharp and free from distracting distortions even as you approach the edge of your vision, greatly enhancing the sense of immersion. The optical coatings contribute to high contrast and excellent light transmission, rendering subtle details in nebulae and galaxies with clarity.
While it performs exceptionally well for its intended purpose, I have noticed that in very high-power applications with larger aperture telescopes, the absolute sharpness might slightly diminish compared to ultra-premium, exotic eyepieces costing several times as much. However, for its price point and specifications, its performance is truly outstanding and comfortably meets, if not exceeds, expectations.
Design & Ergonomics
The build quality of this eyepiece is superb. The all-metal construction feels robust and precise, with smooth mechanical operation. The rubberized eyecup is comfortable and effectively blocks stray light, improving contrast. It has a satisfying heft that suggests quality materials and precise assembly.
Ergonomically, the extended eye relief of 15.3mm is a real boon, making it comfortable for prolonged viewing sessions, even for those who wear glasses. The rubberized eyecup is well-designed, flipping up and down easily and providing a secure resting place for the eye. The knurled grip surfaces on the barrel ensure you can adjust the eyepiece even with gloved hands.
Practical design elements like the clearly marked 20mm focal length and the subtle branding contribute to its professional aesthetic. There’s no superfluous ornamentation, just pure functionality and a focus on optical excellence.
Durability & Maintenance
Given its sealed and argon-purged construction, this eyepiece is designed for long-term durability and minimal fuss. Under normal astronomical observation conditions, I anticipate this unit will last for decades without any discernible degradation in performance. The waterproof design is a significant advantage, offering peace of mind during humid nights or accidental exposure to moisture.
Maintenance is practically non-existent beyond cleaning the exterior lenses. The internal optical path is sealed, preventing dust and moisture from entering. This means no tedious internal cleaning sessions are required, saving time and eliminating the risk of scratching delicate optical surfaces.
The only potential failure point, as with any precision instrument, would be a severe physical impact. However, the robust construction suggests it can withstand moderate bumps and knocks encountered during normal use in an observatory or while transporting it to a dark-sky site.
Accessories and Customization Options
This particular model comes as a standalone eyepiece, without specific accessories like filters or additional caps beyond the basic protective ones. However, its 1.25″ barrel size means it is compatible with a vast array of standard astronomical filters, such as light pollution filters or narrowband filters for observing nebulae. These are readily available from numerous manufacturers and can significantly enhance observing sessions for specific targets.
There are no direct customization options for the eyepiece itself, as it’s a highly engineered optical instrument. However, its compatibility with standard filter threads means you can adapt its performance to different viewing conditions or target types. This universality is a key benefit, allowing you to build a versatile collection of accessories around this excellent optic.
Pros and Cons of Explore Scientific 20mm 68 Degree Series Argon-Purged Waterproof Eyepiece
Pros
- Superb optical quality with excellent sharpness and contrast, particularly for a 68-degree field of view.
- Impressive flat field performance, minimizing distortion towards the edge of the view.
- Argon-purged and waterproof design provides excellent protection against internal fogging and contaminants, ensuring long-term clarity.
- Generous 15.3mm eye relief offers comfortable viewing for extended periods, even for eyeglass wearers.
- Solid, all-metal construction lends a feel of high quality and excellent durability.
Cons
- The price point, while justified for its features, is a significant investment compared to basic eyepieces.
- While excellent, absolute peak performance at the extreme edge of the field might be surpassed by much more expensive, specialized eyepieces.
Who Should Buy Explore Scientific 20mm 68 Degree Series Argon-Purged Waterproof Eyepiece?
This eyepiece is an ideal choice for amateur astronomers seeking a significant upgrade in visual performance and durability. It is particularly well-suited for those who observe in environments with variable humidity or dew, as the argon-purged, waterproof design offers unparalleled protection. Anyone who appreciates a wide, immersive field of view and desires sharp, clear images without the frustration of internal dust or fog will find this optic highly rewarding.
Those who are just starting out with a basic telescope might consider this an advanced purchase, and perhaps a more budget-friendly eyepiece should be prioritized initially. However, if you are an intermediate to advanced observer looking for a workhorse eyepiece that offers excellent all-around performance for general-purpose viewing, planetary observation, and sweeping the Milky Way, this Explore Scientific model is an excellent candidate. For maximum utility, consider pairing it with a 1.25″ broadband or light pollution filter, especially if you observe from a light-polluted area.
Conclusion on Explore Scientific 20mm 68 Degree Series Argon-Purged Waterproof Eyepiece
The Explore Scientific 20mm 68 Degree Series Argon-Purged Waterproof Eyepiece is a standout performer that truly delivers on its promises. Its exceptional optical quality, combined with the robust, sealed design, makes it a reliable and enjoyable instrument for any serious amateur astronomer. The comfortable eye relief and expansive 68-degree field of view contribute to truly immersive observing sessions.
Considering the advanced features, superior optics, and rugged construction, the price of $219.99 represents excellent value for the performance delivered. This is not just another eyepiece; it’s a piece of equipment designed to enhance your connection with the cosmos for years to come. I wholeheartedly recommend this optic to anyone looking for a high-quality, durable, and optically superb eyepiece that can handle challenging observing conditions with grace.