If you’re ready to swap out your standard Plossl eyepieces for oculars that will take your observing game to the next level, you should check out the Orion Telescopes & Binoculars EF Widefield 1.25″ Eyepieces. The “EF” stands for Extra Flat, which means that Orion’s EF Widefield Eyepieces are designed to minimize field curvature at the periphery, so you see an exceptionally flat, non-distorted image. All the internal lenses are fully multi-coated and edge-blackened for superior light transmission and image contrast.
As the name also implies, the fields of view of the EF Widefield Eyepieces are generously expansive to provide a comfortable, immersive view, whether you’re gazing at celestial denizens or land-based subjects. Of the five different focal lengths, the 8mm and 12mm EFs have a 60-degree field of view (FOV), the 16mm and 19mm have a 65-degree FOV, and the 27mm has a 53-degree FOV.
The machined, black-anodized aluminum housings feature a rubber grip band for easy handling, even while wearing gloves, and a slotted barrel to prevent slip-outs if the locking thumbscrew on your telescope’s diagonal or focuser should loosen slightly. The 1.25″ barrels are also threaded to accept an array of Orion 1.25″ filters.
And unlike many wide-angle eyepieces on the market, each Orion EF Widefield Eyepiece sports a rubber-rimmed twist-up eyecup, which not only reduces intrusion of unwanted ambient light, but also helps position your eye at the optimal distance from the eye lens to allow visibility of the entire field of view. Eye relief (ER) varies depending on the focal length: the 8mm EF Widefield Eyepiece has 10mm ER, the 12mm has 15mm ER, the 16mm has 18mm ER, the 19mm has 18.5mm ER, and the 27mm has 23mm ER.
From the low-power 27mm to the high-power 8mm focal length, Orion’s EF Widefield 1.25″ Eyepieces are sure to provide a “step up” for anyone looking for a flatter, wider-field window on the universe than standard Plossl or Kellner eyepieces can deliver