All About the Explore Scientific 2in 99% Reflectivity Diagonal Mirror: Start Here
For years, my telescope setup has been a work in progress, a constant quest to wring the most detail and brightness from the faint light of distant celestial objects. The achilles’ heel in this pursuit often lies not with the telescope’s optics, but with the accessories that guide that precious light to my eye. My previous diagonal, while functional, was starting to show its age, exhibiting slight internal reflections and a noticeable dip in brightness on fainter targets. This led me to seek out a premium replacement, something that would truly preserve the integrity of the image the telescope worked so hard to gather. I eventually settled on the Explore Scientific 2in 99% Reflectivity Diagonal Mirror, drawn by its promise of superior light transmission.
My initial impression upon unboxing this diagonal was one of solid craftsmanship. The unit feels substantial without being overly heavy, and the metalwork is precisely machined. It’s a far cry from some of the flimsier alternatives I’ve encountered over the years. I had briefly considered a competitor’s offering known for its dielectric coatings, but the specific mention of 99% reflectivity on this Explore Scientific model, combined with a slightly more accessible price point, tipped the scales. A quick glance confirmed its thoughtful design, and I felt a surge of anticipation, a practical satisfaction that this upgrade would likely solve my perceived imaging issues.
Real-World Testing: Putting Explore Scientific 2in 99% Reflectivity Diagonal Mirror to the Test
First Use Experience
My testing ground for this diagonal has been my backyard observatory, under skies ranging from the moderately light-polluted suburban glow to the darker, more pristine conditions found on camping trips far from city lights. The primary test was its integration into my refractor and reflector telescopes, both of which accept standard 2-inch accessories. I inserted eyepieces ranging from wide-field 2-inch Plössl designs to high-magnification narrow-field orthoscopics, evaluating the optical path meticulously.
During these initial sessions, the difference was immediately apparent. The 99% reflectivity specification wasn’t just marketing jargon; faint nebulae appeared more prominent, star fields resolved with greater clarity, and the overall brightness and contrast were noticeably enhanced, especially with my longer focal length telescope. There was no discernible internal glare or false light, even when imaging brighter objects like the Moon or Jupiter. Inserting and removing the diagonal from the focuser was a smooth, precise action, thanks to its well-machined barrel and compression ring.
Extended Use & Reliability
After several months of regular use, including numerous nights under the stars and periods of storage in my equipment case, the Explore Scientific 2in 99% Reflectivity Diagonal Mirror has held up exceptionally well. There are no signs of wear on the reflective surface, and the internal baffling remains clean and effective. The compression ring mechanism continues to grip eyepieces securely without scratching their barrels.
Maintaining this diagonal is refreshingly simple. A gentle puff of air is usually sufficient to clear any minor dust that might settle on the mirror, and for more stubborn particles, a specialized optic cleaning solution and a lint-free cloth can be used with care. Unlike some diagonals that can develop internal fogging or degradation over time, this mirror-coated unit has shown no such issues. Compared to my previous, older diagonal, which required periodic internal cleaning to combat subtle light scatter, this Explore Scientific offering requires far less fuss and consistently delivers a superior viewing experience.
Breaking Down the Features of Explore Scientific 2in 99% Reflectivity Diagonal Mirror
Specifications
The Explore Scientific 2in 99% Reflectivity Diagonal Mirror boasts a set of specifications that speak to its premium nature. It features a 2-inch barrel designed to accept standard 2-inch astronomical eyepieces and accessories, ensuring broad compatibility with most telescopes. The core of its performance lies in the 99% reflectivity dielectric mirror, a significant upgrade over standard aluminum or silver coatings that typically reflect closer to 90-95% of incident light.
This high reflectivity translates directly into brighter, more detailed views. The mirror is housed within a robust casing, contributing to the overall 1 lb; .45kg weight, which feels substantial and well-built. The diagonal measures approximately 104.8mm in length, 60.9mm in width, and 127.0mm in height, providing a comfortable viewing angle without adding excessive length to the optical train. This thoughtful design minimizes any potential for image degradation, ensuring that the light gathered by your telescope reaches your eye with maximum fidelity.
Performance & Functionality
The primary job of a diagonal mirror is to redirect light from the telescope’s objective to your eyepiece at a comfortable 90-degree angle, and the Explore Scientific 2in 99% Reflectivity Diagonal Mirror excels at this. Its 99% reflectivity is the standout performance feature, resulting in noticeably brighter images. This enhancement is particularly crucial when observing faint deep-sky objects like nebulae and galaxies, where every photon counts.
The dielectric coating is also key to its superior performance, offering a clean reflection with minimal color fringing. I found that the detail on planetary surfaces, like Jupiter’s cloud bands or Saturn’s rings, appeared crisper and more defined than with my older diagonal. The solid construction also means it stays aligned reliably, preventing the subtle shifts that can plague less well-made accessories. Its main strength is undeniably its light-gathering efficiency and image clarity.
Design & Ergonomics
The design of this diagonal is both practical and aesthetically pleasing. The solid construction and use of quality materials are evident from the moment you pick it up. The black anodized metal body feels sturdy and durable, and the internal baffling is well-executed to prevent stray light from entering the optical path.
Ergonomically, the 2-inch barrel fits snugly into my telescope’s focuser, and the integrated compression ring allows for easy, secure insertion and removal of eyepieces. This is a welcome feature, as it prevents accidental scratches on expensive eyepieces and ensures a firm grip. The overall size and shape are balanced, making it easy to handle and maneuver without feeling cumbersome. It’s clear that Explore Scientific has put a lot of thought into how this accessory will be used in real-world observing scenarios.
Durability & Maintenance
Based on its robust build and material quality, I anticipate the Explore Scientific 2in 99% Reflectivity Diagonal Mirror to have a long service life. The dielectric mirror coating is known for its durability and resistance to degradation compared to older silver or aluminum coatings, which can oxidize or corrode over time. I’ve experienced no issues with scratching or flaking of the reflective surface, even with repeated use and eyepiece changes.
Maintenance is straightforward, primarily involving keeping the mirror surface clean to maintain optimal reflectivity. Unlike some eyepieces or optical tubes that can trap moisture or dust internally, this diagonal’s design is relatively simple to keep clear. A careful dusting or light cleaning with appropriate solutions is all that’s generally needed. The lack of complex internal mechanisms also reduces potential points of failure, contributing to its overall reliability.
Accessories and Customization Options
The Explore Scientific 2in 99% Reflectivity Diagonal Mirror primarily functions as a standalone accessory, meaning it doesn’t typically come with a wide array of accompanying accessories. Its main value is in its optical performance and build quality. However, it is designed to work seamlessly with any standard 2-inch astronomical eyepieces, which are the primary “accessories” users will attach to it.
There are no real customization options for the diagonal itself, as its core function is fixed. However, the 2-inch barrel is compatible with adapters that can accept 1.25-inch eyepieces, though using such an adapter would introduce a secondary optical element (the adapter itself) that could slightly degrade the image quality compared to using the diagonal with 2-inch eyepieces. The focus is on its direct use with high-quality 2-inch optics.
Pros and Cons of Explore Scientific 2in 99% Reflectivity Diagonal Mirror
Pros
- Exceptional Brightness: The 99% reflectivity of the dielectric mirror delivers noticeably brighter images, especially for faint deep-sky objects.
- Superior Image Clarity: Minimizes internal reflections and light scatter for cleaner, crisper views with enhanced contrast.
- Robust Build Quality: Constructed with high-quality materials and precise machining, giving it a durable and premium feel.
- Wide Compatibility: The standard 2-inch barrel fits most telescopes and accepts a wide range of 2-inch eyepieces.
- Easy Maintenance: Simple to clean and care for, ensuring consistent performance over time.
Cons
- Price Point: It represents a significant investment compared to basic diagonals, reflecting its premium performance.
- Not for 1.25-inch Focusers (Directly): While adaptable, it’s primarily designed for telescopes with 2-inch focusers to fully leverage its capabilities.
Who Should Buy Explore Scientific 2in 99% Reflectivity Diagonal Mirror?
This diagonal is an excellent choice for serious amateur astronomers who are looking to maximize the performance of their telescope. If you own a quality refractor or reflector with a 2-inch focuser and are frequently observing faint nebulae, galaxies, or other low-contrast targets, this diagonal will offer a significant improvement. It’s particularly beneficial for those who have already invested in high-quality, wide-field 2-inch eyepieces and want to ensure they are getting the most out of them.
However, beginners with smaller telescopes or those primarily observing the Moon and planets through a 1.25-inch focuser might find the investment less justifiable, as the benefits are most pronounced with fainter objects and wider fields of view. While it’s adaptable to 1.25-inch eyepieces with an adapter, it’s truly in its element when paired with premium 2-inch optics. You might also consider getting a set of high-quality 2-inch eyepieces if you don’t already own them, as they are essential to fully appreciate what this diagonal offers.
Conclusion on Explore Scientific 2in 99% Reflectivity Diagonal Mirror
The Explore Scientific 2in 99% Reflectivity Diagonal Mirror is, without question, a premium accessory that lives up to its specifications. Its 99% reflectivity and dielectric coating translate into a tangible improvement in image brightness and clarity, making faint celestial objects reveal more of their subtle beauty. The solid construction and thoughtful design ensure it will be a reliable part of an astronomical setup for years to come.
While the price is higher than many alternatives, the enhanced viewing experience it provides, especially for deep-sky astronomy, justifies the investment for dedicated observers. If you are seeking to extract every last bit of detail and light from your telescope, and you are equipped with a 2-inch focuser and compatible eyepieces, then this diagonal comes with a strong recommendation. It’s a well-crafted piece of equipment that genuinely elevates the observing experience.