Explore Scientific 100° Series 2" 25mm Waterproof Eyepiece

Explore Scientific 100° Series 2" 25mm Waterproof EyepieceThe 100 Series 25mm is a flagship class ultra wide field eyepiece delivering breathtaking panoramic views through a 2" barrel at low magnification. At 100 with a 25mm focal length, the true field of view is enormous large star forming regions, galaxy clusters, and sweeping Milky Way panoramas fill the eyepiece with an immersive sense of depth that no narrower design can replicate. The premium multi element optical design uses high quality glass types

The 100° Series 25mm is a flagship-class ultra-wide-field eyepiece delivering breathtaking panoramic views through a 2" barrel at low magnification. At 100° with a 25mm focal length, the true field of view is enormous — large star-forming regions, galaxy clusters, and sweeping Milky Way panoramas fill the eyepiece with an immersive sense of depth that no narrower design can replicate.

The premium multi-element optical design uses high-quality glass types to maintain sharp, well-corrected images across the entire hyper-wide field. Even in fast telescopes (f/5 and faster), the 100° series delivers strong edge performance. Argon-purged waterproof construction ensures the optics stay sealed and fog-free through the worst dew and humidity conditions.

At $899, this sits in premium eyepiece territory — but it directly competes with Tele Vue Ethos eyepieces that cost comparably or more, while adding waterproof construction that the Ethos line lacks.

Key Features

• 100° apparent field of view — hyper-wide panoramic framing for the most immersive deep-sky views possible through a 2" barrel
• Premium multi-element optics — high-quality glass types deliver sharp, color-corrected images with strong edge correction across the enormous field
• 2" barrel for maximum light throughput at the long focal length
• Argon-purged waterproof housing — sealed against moisture, fog, and temperature extremes, a feature that most ultra-wide-field competitors lack
• Enhanced Multi-Layer Deposition (EMD) coatings on all air-to-glass surfaces with edge-blackened elements for maximum contrast
• Fold-down silicone rubber eyecup with comfortable eye relief for extended viewing sessions

Ideal For

• Wide-field deep-sky observers who want the most immersive views possible — large nebula complexes, Milky Way star clouds, and galaxy groups at their most expansive within a 100° panoramic field
• Dobsonian and large-aperture telescope owners seeking the ultimate low-power, hyper-wide-field eyepiece for sweeping deep-sky observing
• Observers comparing to Tele Vue Ethos — the 100° series delivers comparable field width and optical quality with the added benefit of waterproof construction
• Star party showcase — the 100° field creates genuine "wow" reactions from both experienced observers and first-time visitors