William Optics UWAN 4mm Eyepiece

The William Optics UWAN 4mm 1.25" Eyepiece is the ultimate high power eyepiece for ultra wide field views, and delivers truly remarkable views of the sky all at an impressive price. Long gone are the times when a high quality eyepiece had to cost an arm and leg.

The super wide field of view offer an outstanding 82 deg ultra-wide field of view . Fully MultiCoated (FMC) glass for excellent light transmittance, reduced chromatic aberration and improved contrast compared to similar eyepieces.

Great contrast, with fully internally blackened (lenses’ edges and internal spacers), no flaring or ghosting on high-contrast objects.

It's light and easy with innovative twist-up rubber eyecup, long eye-relief, 12mm and there are no internal reflections, kidney beaning or other distracting distortions.

This eyepiece has wonderful fit and finish, a high-resistance anodized black barrel, a super smooth design for no hook up in your focuser and threaded for filters’ usage.

William Optics UWAN  4mm 1.25


  • Internally baffled, All lenses' edges and internal spacers blackened, Fully multicoated
  • Focal Length 4 mm
  • Field Stop Diameter 6 mm
  • Lens Structure (#Elements/#Groups) 7/4
  • Field of View 82
  • Eye Relief 12mm
  • Barrel 1.25"
  • Coating FMC
  • Parfocal Yes
  • Weight 200g

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