Designed with a fully multicoated 8-element/5-group lens configuration, the Celestron Ultima Edge 18mm Flat Field Eyepiece produces bright and clear views with crisp and sharp resolution across the wide 65° field of view—even at the extreme edges. The eyepiece's focal length produces a medium magnification that strikes the delicate balance between being able to see details without the appearance of distracting vibrations that can ruin a view. This Ultima Edge has a 1.25" barrel that makes it compatible with popular diagonals, Barlows, and visual backs with standard threads for filters. This version is parfocal with the 10mm and 15mm models in the Ultima Edge series, requiring little or no refocusing when changing between them. A textured collar makes inserting and removing the eyepiece easy, and the combination of long 20mm eye relief and fold-down rubber eyecup make it comfortable to use with or without eyewear.
Focal Length 18mm
Apparent Field of View 65°
Eye Relief 20.0 mm
Eyepiece Barrel Diameter 1.25"
Battery Type Not Specified by Manufacturer
Field Stop Diameter 23.4 mm
Dimensions ø: 2 x L: 3.2" / ø: 51 x L: 81 mm
Weight 7.4 oz / 209.7 g