Pentax XW 3.5mm

Pentax XW 3.5mm

  (1 Review)
✓ 2 year warranty


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About this product

Model:  PentaxXW3.5
Part Number:  70511

The Pentax XW 3.5 is the shortest focal length eyepiece in the XW series with unsurpassed optical clarity and a 70 degree field of view.


  • High-refraction, low-dispersion Lanthanum glass.
  • Pentax Super Multi-Coatings (SMC) on all air/glass surfaces.
  • Edge-blackened optics and optimised baffles minimise internal reflections.
  • Optically corrected for use with focal ratios as fast as f/4.
  • 20mm eye-relief and twist-up rubber-rimmed eyecups - perfect for spectacle wearers.
  • Chromed barrels threaded to accept filters.
  • Weatherproof to JIS Class 4 standards.


Lens Structure: 8 elements, 5 groups
Focal Length: 3.5mm
Apparent Field of View: 70 degrees
Eye Relief: 20mm
Attachment Diameter: 1.25" (31.7mm)
Filter Diameter: 28.6mm
Field Stop Diameter: 4.3mm
Eyepiece Ring: Helicoid type
Height & Width: 5.4" x 2.4"
Weight: 14.3 oz. (405g)

Eyepiece Field of View Simulator

Customer reviews

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Top class eyepiece
Saturday, 13 July 2019  | 

Beautifully engineered eyepiece. Very comfortable, especially the twist-up eye relief adjustment. Extremely sharp view right across the field, which is just right.
Highly recommend for any scope but if you have a fast scope eg Reflector at f5 or faster and have mid-range or telescope stock eyepieces, you will absolutely transform your scope with the XW series.
This is the lowest focal length eyepiece in the series and gives the highest magnification so it is working hard but it produces Fantastically clear and contrasty images with a generous field, nonetheless.


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