Eyepiece Binorum Planetary Pro 7mm 58° 1.25″

Binorum Planetary Pro 7mm 58° 1.25″ Eyepiece

The Binorum Planetary Pro range was created with a clear purpose: to give planetary and lunar observers an eyepiece that combines high contrast and sharpness with genuine viewing comfort. The 7mm model offers an apparent field of view of 58° - significantly wider than a classic orthoscopic or standard Plössl eyepiece - while keeping all the optical strengths those designs are known for. The result is a tool you will appreciate at first glance of Saturn's rings and after hours of patient planetary observation alike.

Six-element optics - a carefully considered choice

At the heart of the Planetary Pro is a carefully optimised six-element optical formula. Four-element designs are simple, but their field of view is narrower. Complex wide-field eyepieces with nine or more elements often suffer from scattered light or lateral chromatic aberration - exactly the kind of problem you do not want when looking at a bright planet. Six elements represent the middle path: a 58° apparent field of view without any loss of contrast and without the stray reflections that reduce the visibility of fine surface detail.

Every air-to-glass surface carries broadband FMC (Fully Multi-Coated) anti-reflection coatings. This means that the maximum amount of light reaches your eye rather than scattering inside the barrel. The on-axis image - where your attention is focused during planetary observation - is sharp and contrastive across the entire field of view. Fine details such as the Cassini Division in Saturn's rings or the cloud belts of Jupiter appear with a clarity you will quickly come to rely on.

Comfortable eye relief - even with glasses

A short focal length planetary eyepiece usually means pressing your eye uncomfortably close to the lens. The Planetary Pro 7mm breaks that habit. For its focal length, the eye relief is surprisingly generous, allowing comfortable viewing even with spectacles on. The adjustable twist-up rubber eyecup can be raised or lowered smoothly to suit your preferred eye position and folds neatly away when you are not wearing glasses. During long observing sessions, this seemingly small feature matters far more than it first appears.

The extended eye relief also has another practical benefit: it virtually eliminates kidney-beaning - the annoying black shadow that appears with short eye relief eyepieces whenever you move your head even slightly. Being able to track a planet without constantly searching for the correct eye position is a genuinely different experience.

Fully baffled interior for maximum contrast

Optical performance depends not only on the lenses but also on what happens inside the barrel. The interior of the Planetary Pro is fully blackened, all internal baffles carry anti-reflection micro-textured surfaces, and complete black anodising minimises any stray light. The edges of the lenses are carefully blackened to prevent reflections that would reduce contrast when looking at bright objects. The Moon and planets at high magnification are precisely the targets where stray light has the greatest impact. The result is an image with a clean, dark background and well-defined detail.

What can you observe with this eyepiece?

The Planetary Pro 7mm is designed primarily for observing planets and the Moon, but its usefulness goes further. On the Moon it reveals intricate crater detail, rilles and the shadows of mountain ridges with outstanding three-dimensional quality. On Jupiter you can make out the Great Red Spot and the structure of the cloud belts. On Saturn the Cassini Division is clear, and under good seeing conditions the Encke Gap becomes visible too. Mars will show the polar caps and darker surface features depending on how close the planet is at the time. The high magnification and sharp optics also make this eyepiece a reliable choice for splitting close double stars and for observing planetary nebulae and globular clusters.

The eyepiece is also suitable for afocal projection photography with a DSLR or a compact digital camera, so it will serve those who want to capture what they see.

Calculating magnification

To find the magnification this eyepiece will give with your telescope, simply divide your telescope's focal length by 7. The table below shows examples for common focal lengths.

Technical specifications

About Binorum

Binorum eyepieces are built with a straightforward goal: to bring observers the optical performance that once belonged only to far more expensive products. The brand was founded by astronomers for astronomers - people who spend hours at the telescope themselves and know what truly makes a difference. The Binorum philosophy is to select every design element for its real contribution to the observing experience, not for its marketing appeal. The result is a wide range of astronomical eyepieces and accessories where every product passes rigorous quality control and meets demanding optical standards. If you are looking for a reliable companion for the night sky, Binorum is a choice that holds up in practice.