Pentax XW40-R 40mm Wide-Angle Eyepiece (2-inch)

SKU: 70538

Starting at $39/mo

Need help deciding? Contact us right now!

In the box

Pentax XW40-R 40mm Wide-Angle Eyepiece (2-inch)

  • Pentax XW40-R 40mm Wide-Angle Eyepiece (2-inch)

From The Wavelength Blog Read more

Pentax XW40-R 40mm Wide-Angle Eyepiece (2-inch)

Ricoh Imaging is pleased to announce the release of the Pentax XW40-R Eyepiece as part of the Sports Optics Line. This eyepiece offers a 70-degree field of view for comfortable viewing. It is specially designed to offer an excellent field of view while the fully multi-coated lenses increase light transmission and color quality. It provides ideal viewing when used with a telescope for viewing the nebula, planets and exploring the night sky.

Long-Focal-Length Eyepiece

Thanks to its long-focal-length design, this eyepiece will let you observe large celestial bodies spreading across the night sky, such as the Pleiades star cluster and the Andromeda Galaxy, in their entirety when mounted on an astronomical telescope with a focal length of 1000mm.

70-Degree Apparent Angle of View and 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.

High-Grade Optics for Exceptional Image Quality

The high-performance XW-series optics incorporates high-refraction, extra-low-dispersion lanthanum glass elements to produce a well-balanced image with minimal aberrations. It is particularly designed to reduce the disturbing blackout effect by effectively compensating the spherical aberration of the pupil.

Pentax Multi-Layer Coating

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.

Advanced Light-Shielding Technology for Improved Image Contrast

Thanks to Pentax’s advanced computer simulation technology, the XW series features a light-shielding diaphragm at the most effective position to drastically reduce internal reflections for a brighter, higher-contrast image.

Comprehensive Lineup to Accommodate All Applications

Featuring functional, practical focal lengths, the XW eyepiece series provides a comprehensive lineup that accommodates all types of applications, from low-magnification viewing of stars to high-magnification observation of planets.

Weatherproof Construction for All-Weather Viewing

The XW series features JIS Class 4 weatherproof construction, making it possible to use it in drizzle or under night dew. Please note that this series is not designed for underwater use and should not be submerged.

Sleeve Size and Eyecup Design

This eyepiece provides a 50.8mm (2-inch) installment diameter. When you remove the screw-on eyecup, the XW40-R model provides a screw thread with a 48mm diameter and a 0.75 pitch.


Eyepiece TypeFixed Eyepieces
Barrel Diameter2"
Focal Length40mm

Same Day Shipping

All orders placed by 4PM( EST), Monday through Thursday, and by 11AM (EST) on Friday, are shipped same day. Orders placed outside these times will ship the next business day. We do not ship internationally or to Puerto Rico, Guam and other US territories at this time. For more details click here.

Free Two-Day Shipping

We offer free expedited shipping on thousands of items within the continental USA (this does not include Alaska and Hawaii).

Flexible, Easy Returns

If you're not happy with your purchase for any reason, our flexible 30-day free return policy makes it easy to get a full refund. Click here to view our return policy.

Ratings and reviews