DESCRIPTION
Pentax XW 3.5mm 1.25" 70° Telescope Eyepiece
The 3.5 mm XW, 1.25-Inch Pentax Eyepiece, like each eyepiece in its series, the XW 3.5 eyepiece is designed specifically to provide ideal ground and astronomical observations with a telescope
Key Features
70° Apparent Field of View & 20mm Eye Relief
All smc PENTAX XW-series eyepieces feature an extra-wide 70-degree apparent angle of view and an extra-long 20mm eye relief to deliver an exciting, wide-perspective image. If you look at the simulation to the left, you will notice that the images have the same magnification, but the Pentax XW eyepiece has an increase viewing area.
Pentax XW 20mm Field of View
20mm Plossl Field of View
*Simulation based on 8" f/10 SCT
High-Grade Optics
The high-performance XW-series optics incorporates high-refraction, extra-low-dispersion lanthanum glass elements to produce a well-balanced image with minimal aberrations. These eyepieces were designed to reduce the disturbing blackout effect by compensating the spherical aberration of the pupil.
All lens surfaces that come in contact with air are treated with the original multi-layer coating, while all laminated surfaces are treated with the innovative partial coating, to offer the light transmission efficiency of more than 90 percent (an astonishing 96 percent at 550nm) over the visible light spectrum.
Weatherproof Construction
The XW series features JIS Class 4 weatherproof construction,* making it possible to use it in drizzle or under night dew.
* The XW-series eyepieces are not designed for underwater use and should not be submerged under water.
SPECIFICATIONS
| Elements/Groups | 8/5 |
| Eye Relief | 20mm |
| Eyepiece Barrel Size | 1.25" |
| Eyepiece Diameter | 61mm |
| Eyepiece Length | 137mm |
| Eyepiece Type | Fixed |
| Eyepiece Weight | 0.89lbs |
| Field of View | 70 Degrees |
| Focal Length | 3.5 mm |