Binorum Advanced 6mm 66° FMC 1.25″ Eyepiece
Advanced Series - Best Price-to-Performance Ratio
The Binorum Advanced eyepiece series offers the best price-to-performance ratio on the astronomical eyepiece market. These super wide-angle eyepieces with a 66° field of view combine advanced optical construction with affordable pricing, making them the ideal choice for astronomers seeking premium performance without premium prices. The Advanced series represents a significant upgrade over basic eyepieces supplied with telescopes while offering features typically available only in considerably more expensive models.
Super Wide-Angle 66° Field of View
The super wide-angle Binorum Advanced eyepiece with a 66° apparent field provides an immersive observing experience that dramatically exceeds standard eyepieces. The 66° field of view surpasses the image field size of popular Erfle-type eyepieces, enabling easy object location - particularly valuable for beginning observers. A wider apparent field means you see more of the sky at once, objects remain in the field longer as Earth rotates, and the overall observing experience becomes significantly more immersive.
Advanced 5-Element Optical Construction
The eyepiece features a 5-element optical design with glass lenses and multiple anti-reflection FMC (Fully Multi-Coated) layers on all optical surfaces. This advanced optical assembly ensures excellent image sharpness, high contrast, and faithful color rendition across the entire field of view. The five-element construction is specifically optimized for wide-angle design, providing good image correction right to the field edges - quality typically available only in substantially more expensive eyepieces.
Exceptionally Long 16mm Eye Relief
One of the greatest advantages of the Advanced series is the generous 16mm eye relief, providing comfortable viewing even during extended observing sessions. This liberal eye relief allows relaxed eye positioning without needing to press uncomfortably close to the eyepiece, significantly reducing eye fatigue. The long eye relief proves particularly advantageous for eyeglass wearers and makes observing more comfortable for all users regardless of experience level.
Technical Specifications
- Focal length: 6mm
- Apparent field of view: 66°
- Eye relief: 16mm
- Barrel diameter: 1.25″ (31.7mm)
- Optical design: 5-element configuration
- Coatings: FMC (Fully Multi-Coated) on all surfaces
- Lens material: Optical glass
- Housing: All-metal construction
- Eyecup: Rubber fold-down design
- Filter threads: 1.25″ standard threads
High Magnification for Planetary Observation
With a 6mm focal length, this eyepiece provides high magnification ideal for detailed planetary and lunar observation. Combined with a 750mm focal length telescope, you achieve 125x magnification; with a 1200mm telescope, you reach 200x - excellent for resolving fine details on Jupiter, Saturn's rings, and lunar craters. The wide 66° field at this high magnification provides ample room for tracking objects as Earth rotates without constantly adjusting telescope pointing.
Quality All-Metal Construction
The eyepiece is manufactured with quality all-metal construction ensuring durability and precision. The metal barrel fits securely in the focuser without play, critical for maintaining sharp focus at high magnifications. Robust construction withstands regular field use and ensures long eyepiece lifespan.
Rubber Fold-Down Eyecup
The eyepiece features a comfortable rubber fold-down eyecup that shields against stray light from the sides and can be folded down for eyeglass wearers. The eyecup helps maintain proper eye distance from the lens and increases comfort during long observing sessions.
Filter Threads for Expanded Capabilities
The barrel includes standard 1.25″ filter threads, enabling use of moon filters to reduce glare, color filters to enhance planetary contrast, or nebula filters for deep-sky object observation. This versatility makes Advanced eyepieces even more multifunctional.
Ideal Replacement for Stock Eyepieces
Advanced eyepieces replace and dramatically expand the capabilities of eyepieces supplied with telescopes. While most telescopes come with basic eyepieces featuring narrow fields of view (typically 40-52°) and limited optical quality, the Advanced series provides professional performance with a wide 66° field, high display quality, and excellent viewing comfort - all for a fraction of the price of typical wide-angle eyepieces from premium brands.
Surprisingly Good Image Correction
Despite the affordable price, Advanced eyepieces exhibit surprisingly good image correction across the entire field of view. While inexpensive wide-angle eyepieces often suffer significant image degradation toward field edges, the Advanced series maintains usable sharpness and contrast right to the edges - the result of carefully designed 5-element optical construction and quality FMC coatings.
Available Focal Lengths in the Advanced Series
The Binorum Advanced series is available in three carefully selected focal lengths:
- 6mm - high magnification for detailed planetary observation and lunar studies
- 9mm - versatile medium-high magnification for planets, Moon, and brighter deep-sky objects
- 15mm - medium magnification for wide-angle Moon views, star clusters, and extended nebulae
These three focal lengths cover the most important magnification range for most observing programs and provide optimal magnification steps for different object types and atmospheric conditions.
Who is the Advanced Series For?
Binorum Advanced eyepieces are ideal for:
- Beginning astronomers seeking an upgrade from stock eyepieces
- Experienced observers building a quality eyepiece collection on a limited budget
- Astronomers who appreciate wide-angle fields without high prices
- Eyeglass wearers thanks to the generous 16mm eye relief
- Anyone seeking the best price-to-performance ratio in the super wide-angle eyepiece category
Easy Object Location
The wide 66° field of view of the Advanced series significantly facilitates finding and centering objects in the sky. More sky visible at once means you can more easily use "star hopping" techniques to locate fainter objects. This proves particularly valuable for beginning observers still learning to navigate the night sky.
Why Choose Binorum Advanced Eyepieces
The Binorum Advanced series represents a breakthrough in quality wide-angle eyepiece accessibility. It combines advanced optical properties - 66° field of view, 5-element construction, FMC coatings, long eye relief - with price accessibility that makes these eyepieces available to a broad spectrum of astronomers. While other super wide-angle eyepieces with similar specifications often cost two to three times as much, the Advanced series provides comparable performance for a fraction of the price. Careful optical design ensures good image correction, quality metal construction guarantees durability, and generous eye relief provides comfort during extended observing sessions. For astronomers seeking maximum value for their investment, the Advanced series represents an unbeatable choice - truly the best price-to-performance ratio on the astronomical eyepiece market.
