Thousand Oaks 4.25" Solarlite Film Solar Filter

Thousand Oaks SolarLite 4.25" Solar Filter (S-4250)

Premium Solar Protection for 4.25" Aperture Telescopes

The Thousand Oaks SolarLite 4.25" Solar Filter (Part #S-4250) is purpose-built for safe solar observation with telescopes that have an outer diameter of approximately 4.25 inches. Whether you're viewing sunspot activity, tracking solar eclipses, or doing solar outreach, this filter provides the high-contrast, optically clean views that experienced observers demand.

This filter features Thousand Oaks' exclusive SolarLite film—an advanced solar material that merges the image quality of glass with the ruggedness of polymer. The result is a safe, lightweight, and durable filter that offers reliable performance without the drawbacks of traditional thin-film designs.

Key Features:

• Optically Sharp SolarLite Film: Offers exceptional image clarity and contrast for observing solar surface detail

• Rugged Yet Lightweight: Tear-resistant and impact-resistant polymer won’t scratch, dent, or degrade like some alternatives

• Field Friendly: Won’t require rebalancing your telescope or complex mounting

• Secure Fit: Comes with ample felt lining to provide a snug, scratch-free fit on most 4.25" optical tubes or dew shields

Compatibility:
Fits telescopes with an outer diameter of approximately 4.25 inches. Always measure your telescope's front cell or dew shield to ensure a proper and secure fit before ordering.

Clear Aperture: 90mm or 3.50"

Cell OD:  108mm or 4.25"

SolarLite Film Technology:
After years of research and development, Thousand Oaks Optical has introduced SolarLite—a new solar film that delivers the optical sharpness of glass with the durability and resilience of a polymer. Unlike traditional solar films, SolarLite won’t develop pinholes or surface scratches that could compromise safety. It’s lightweight, so it won’t require rebalancing your optical tube assembly, and it's built to withstand the rigors of field use.

SolarLite offers a consistent yellow-orange solar image across the entire aperture with excellent contrast and uniform density. Its smooth, flat surface ensures sharper views compared to other thin-film filters that often suffer from wrinkles and creases. Tear-resistant, puncture-proof, and more rugged than any other solar film available, SolarLite sets a new standard for safe, high-quality solar observing.

Safety Note:
Before each use, inspect your solar filter for any damage or defects. Never observe the Sun without a securely attached, undamaged filter in place.

Tech Details: