Binorum Planetary Pro 7.5mm 58° 1.25″ Eyepiece

Binorum Planetary Pro 7.5mm 58° 1.25″ Eyepiece

The Binorum Planetary Pro series was created to meet a specific need: to give planetary and lunar observers an eyepiece that combines high contrast and sharp optics with genuine viewing comfort. The 7.5mm focal length model offers an apparent field of view of 58° - significantly wider than classic orthoscopic or standard Plössl eyepieces - while keeping their well-known optical strengths. The result is an eyepiece you will appreciate on your first look at Saturn's rings and equally during hours of patient planetary observation. You no longer have to choose between a wide field and image quality.

Six-element optics - a well-balanced design

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

Fully multi-coated optics for maximum light transmission

Every air-to-glass surface carries broadband multi-layer anti-reflection coatings. This ensures that the maximum amount of light reaches your eye rather than scattering inside the barrel. The image on the optical axis - where you concentrate during planetary observation - is sharp and contrasty 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 - suitable for glasses wearers

A short focal length planetary eyepiece usually means pressing your eye uncomfortably close to the lens. The Planetary Pro 7.5mm breaks with this habit. The eye relief is surprisingly generous for this focal length, allowing comfortable observation even with glasses on. The adjustable threaded rubber eyecup can be smoothly raised or lowered to match your preferred eye position, and folds neatly away when you are not wearing glasses. During long observing sessions, this seemingly small feature makes more difference than you might expect.

No kidney-beaning - relaxed, focused observing

The generous eye relief has another practical benefit: it virtually eliminates the kidney-beaning effect - the annoying dark shadow that appears in eyepieces with short eye relief whenever your head moves slightly. Observing a planet without constantly searching for the correct eye position is simply a different experience - calmer, more focused, and less tiring for your eyes.

Fully blackened 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-damping treatment, and full anodising minimises any light scatter. The edges of the lenses are carefully blackened to prevent reflections that would reduce contrast when viewing bright objects. The Moon and planets at high magnification are precisely the objects where stray light shows most clearly. The result is an image with a clean, dark background and well-defined detail, where nothing distracts you from what matters.

What can you observe with this eyepiece?

The Planetary Pro 7.5mm is designed primarily for observing planets and the Moon, but its uses go further. On the Moon it reveals intricate crater detail, rilles and the shadows of mountain ridges with exceptional three-dimensional appearance. On Jupiter you can distinguish the Great Red Spot and the structure of the cloud belts. On Saturn you will see the Cassini Division, and in good seeing conditions the Encke Gap too. Mars shows its polar ice caps and darker surface features depending on the planet's current distance. The high magnification and sharp optics also make it a reliable tool for splitting close double stars, or for observing planetary nebulae and globular clusters - in short, anywhere that rewards a closer look.

The eyepiece is also suitable for afocal projection photography with a DSLR or compact digital camera, making it useful for anyone who wants to capture what they see and share their images.

How to calculate magnification

To find the magnification this eyepiece gives with your telescope, divide your telescope's focal length by 7.5mm. Here are some examples for common focal lengths:

Technical specifications

About Binorum

Binorum eyepieces are built with a clear purpose: to bring observers optical performance that was once found only in much higher price categories. The brand was built by astronomers for astronomers - people who spend hours at the telescope themselves and know what truly matters. The Binorum philosophy is to select design elements based on their real contribution to the observing experience, not on marketing appeal. The result is a wide range of astronomical eyepieces and accessories, where every product passes thorough quality control and meets demanding optical standards. If you are looking for a reliable partner for the night sky, Binorum is a choice that holds up in practice.