Binorum Super Plössl 15mm 50° SPL 1.25″ Eyepiece
The Workhorse of Medium-Power Observation
Super Plössl construction with a 50° field of view delivers everyday reliability - suitable for every telescope configuration. Binorum Super Plössl eyepieces represent contemporary Plössl designs with outstanding optical capabilities that exceed standard eyepiece performance. The 15mm focal length has earned its reputation as one of the most frequently used focal lengths among amateur astronomers, offering an ideal compromise between magnification and field coverage that makes it indispensable for varied observing programs.
Stellar Performance Across Multiple Targets
These eyepieces shine when observing the Moon and planets, where their optical characteristics deliver satisfying views that reveal genuine detail. Noted for exceptional brightness and outstanding color fidelity, they transition seamlessly to other astronomical subjects. The 15mm focal length provides moderate magnification that works effectively across an unusually broad range of celestial objects - from expansive lunar landscapes to planetary disks, from scattered open clusters to compact globular clusters, making it genuinely versatile.
Professional Optical Refinements
Lens edges receive specialized blackening treatment throughout these Super Plössl eyepieces to ensure superior contrast and suppress unwanted internal reflections. Advanced FMC (Fully Multi-Coated) multi-layer coatings applied across all optical surfaces provide excellent light transmission, sharp image definition, and precise color accuracy. These professional coatings work to minimize light loss through the optical train while eliminating ghost images and internal scatter that degrade image quality. Rubber fold-down eyecups shield against stray light intrusion while offering comfortable viewing positions for extended observation sessions.
Comfortable 9.7mm Eye Relief
The 15mm Super Plössl features a generous 9.7mm of eye relief, providing relaxed viewing comfort that reduces eye strain during lengthy observing sessions. This substantial eye relief allows natural eye positioning without requiring you to press uncomfortably close to the lens, making it suitable for most observers and contributing to fatigue-free astronomy. The comfortable viewing distance proves particularly valuable during extended lunar studies or patient planetary observation when you may spend 30 minutes or more at the eyepiece.
Practical Magnification Range
The 15mm focal length delivers useful magnification across various telescope types. With a 750mm focal length telescope, it provides 50x magnification - perfect for framing the entire lunar disk with room to spare or viewing large star clusters like the Pleiades. Paired with a 900mm instrument, you achieve 60x magnification, excellent for general planetary viewing and detailed lunar exploration. At 1500mm focal length, the eyepiece reaches 100x, offering strong planetary detail while remaining forgiving of atmospheric turbulence.
Technical Specifications
- Focal length: 15mm
- Apparent field of view: 50°
- Barrel diameter: 1.25″ (31.7mm)
- Optical design: 5-element Super Plössl configuration
- Lens coatings: FMC (Fully Multi-Coated) on all surfaces
- Eye relief: 9.7mm
- Lens edge treatment: Blackened for contrast enhancement
- Filter threads: Standard 1.25″ threads
- Housing: All-metal precision construction
- Eyecup: Rubber fold-down design
Extensive Eyepiece Series
The Super Plössl series offers a comprehensive focal length selection: 6mm, 6.4mm, 7.5mm, 8mm, 10mm, 12mm, 12.5mm, 15mm, 17mm, 18mm, 20mm, 25mm, 32mm, and 40mm. This complete range enables astronomers to assemble matched eyepiece sets with properly spaced magnification intervals optimized for their telescopes and observing objectives.
Diverse Observing Applications
The 15mm focal length demonstrates remarkable versatility across observing programs. For lunar observation, it frames substantial regions of the Moon while maintaining sufficient magnification to reveal crater details, mountain ranges, and mare boundaries - ideal for studying how lighting changes along the terminator reveal topographic relief. When observing planets, it provides context views showing planetary disks with major features visible - Jupiter's main cloud belts, Saturn's rings and Cassini Division, and Mars's polar caps during good oppositions. The eyepiece also excels on brighter deep-sky targets including the Orion Nebula's full extent, resolved portions of bright globular clusters like M13, and scattered open clusters across the Milky Way.
The Essential Starting Point
Many experienced observers recommend 15mm as the first quality eyepiece to acquire after purchasing a new telescope, especially for those replacing basic kit eyepieces. Its moderate power provides useful magnification without being overly demanding on atmospheric conditions or telescope tracking, while the comfortable eye relief makes extended viewing sessions pleasant rather than fatiguing. The versatility means you'll continue using it regularly even as your eyepiece collection expands.
Superior 5-Element Design
The Super Plössl 5-element optical configuration offers meaningful improvements over traditional 4-element Plössls: enhanced edge sharpness across the field, improved chromatic correction, reduced internal reflections through optimized spacing, and better contrast on subtle features. Combined with blackened lens edges and complete FMC coating, the design delivers image quality that competes with eyepieces costing significantly more.
Finder and Target Acquisition
Beyond its primary observing roles, the 15mm focal length often serves excellently for initially locating targets before switching to higher magnification. The moderate power combined with the 50° field provides enough sky coverage to find objects using star-hopping techniques while offering sufficient magnification to confirm you've centered the correct target. This makes it valuable for navigating star charts and executing observing lists efficiently.
Why Choose Binorum Eyepieces
Binorum Super Plössl eyepieces combine advanced 5-element optical designs with comprehensive FMC coating systems and precision engineering to deliver professional-grade performance. The blackened lens edges demonstrate attention to contrast optimization found in premium eyepieces, while the generous 9.7mm eye relief ensures viewing comfort during extended sessions. Rigorous quality control maintains consistent performance standards across production, and robust all-metal construction provides long-term reliability. Binorum makes high-quality astronomical optics accessible through intelligent design and efficient manufacturing, enabling observers at all levels to experience the difference that properly engineered eyepieces make in revealing celestial detail.
