Orion 20mm Expanse, 1.25" Eyepiece with 66 Degree Wide Field of View.
The Orion 08923 is a 20mm Expanse Eyepiece with the 66° apparent field of view. Imagine taking in objects like the Andromeda Galaxy, the Double Cluster, or the star clouds in Sagittarius in one sweep. Expanse oculars have big eye lenses and great eye relief (13mm to 17mm). Eyeglass wearers can view the entire field without removing their glasses.
The eyepiece element is fully coated, with the outer lens multi-coated for additional light transmission. Each 1.25" aluminum barrel is threaded for filters and internally blackened to eliminate internal scattering. And their fold-down rubber eyeguards enhance contrast by blocking stray light.
|Eyepiece focal length||20.0mm|
|Apparent field of view||66.0-deg|
|Number of elements||4|
|Field stop diameter||23.5mm|
|Barrel security recess||Yes|
|Blackened lens edges||Yes|
|Dimensions||2.3 in. x 1.3 in.|
|Warranty||Orion 1 year limited warranty|