1000 Oaks Type 2+ Glass Solar Filter - 108mm ID, Full Aperture

1000 Oaks Type 2+ Glass Solar Filter - 108mm ID, Full Aperture
Item # TH-4250
  • This 1000 Oaks Type 2+ Glass Solar Filter has an inner cell diameter of 108mm\4.25" and can be adjusted downward approximately 6mm using the supplied felt shims.
  • Designed to fit Celestron C-90, Meade ETX 90, Questar 3.5, William Optics ZS80II ED, Orion Observer 70 & Astroview 90, Explorer 90.
  • Premium hand-selected glass substrate for lifetime durability.
  • Thousand Oaks Glass Solar Filters incorporate exlusive Solar II Plus coatings.
  • Rejects 99.999% of the solar energy spectrum - from ultra-violet to infrared.
  • Thousand Oaks Glass Solar Filters feature a custom-machined spun aluminum cell to exclusively fit your telescope.
  • Provides an aesthetically pleasing yellow-orange solar image against a black background sky!


Thousand Oaks Full Aperture Glass Solar Filter

Long before the solar observing revolution began, there was Thousand Oaks Optical. Founded more than 30 years ago, Thousand Oaks Optical products now fly above the Earth in NASA's Space Shuttle and serve on the ground for users such as ABC, BBC, CBS, NBC, NOVA, The Discovery Channel, National Geographic and most major universities and observatories throughout the world. Originally located in Thousand Oaks, California and open for business in 1979, this small staff of dedicated professionals have produced literally tens of thousands of solar filters over the years. No wonder millions of solar observers world wide know the Thousand Oaks Optical name!

Thousand Oaks Solar Filters are an observing standard. The Thousand Oaks Type 2+ Glass solar filter was created from high quality hand selected glass which is in turn coated with the exclusive metallic Solar II Plus - simply the most durable on today's market. Thin layers of vacuum-deposited nickel and chrome are applied on the inside surface of the glass substrate, keeping the coating shielded from damage during use. Thousand Oaks Solar II Plus coatings reject 99.999% of the solar energy spectrum - from ultra-violet to infrared. This ensures complete safety for both your eyesight and your telescopes optics! The glass filter elements are then placed into a polished friction-fit spun aluminum cell which is custom tailored to your telescope's outer aperture diameter specifications. A wide exterior cell band is then lined with supplied self-adhesive felt strips for a secure fit. This design helps to prevent heat from building up inside the telescope tube, protecting its exterior and interior components. No danger of a cracked mirror or eye damage... If handled with care, your Thousand Oaks Solar Filter should last a lifetime! Providing a aesthetically pleasing yellow-orange solar image against a black background sky, your Thousand Oaks Type 2+ Filter will show dark umbra and dispersing penumbra sunspot regions, as well as convection-cell granulation on the Sun's surface.

Thousand Oaks Solar Filters Features

  • Wide exterior cell band.
  • Custom self adhesive felt liners for a perfect fit.
  • Most durable coating available on today's market.
  • The safety of this product is guaranteed by ensuring the coating has a transmission of 0.001% or less.
  • All solar filters are covered by a limited liability warranty from defects in material and workmanship.
Thousand Oaks Optical Product Number: 4250
Additional Information

Additional Information

SKU TH-4250
Manufacturer Thousand Oaks
White Light Filter Material Type 2+ Coated Glass
Glass, Film, or Herschel? Glass Filter
Filter OD Size in Inches 4.1" - 6"
Full Aperture or Off-Axis? Full Aperture
Warranty 5 Year Warranty
Filter Diameter 4.25"
Filter Fits Telescope OD Range of... 108mm

Customer Reviews 1 item(s)

Well made,
Filter is well made.installed the felt strip inside the housing and it was a light fit on the scope. I did put a piece of tape on the mount to secure it if I accidentally pointed the scope down. Was able to view sun spot activity just prior to a large solar flare this month
1= Houston, We Have a Problem & 5= It's Out of This World
Review by Jim B / (Posted on 9/25/2014)
Included Items

Included Items

  • 1000 Oaks 4.25" Type 2+ Glass Solar Filter
  • Self Adhesive Felt Strips
Questions & Answers

Product Questions

I have a Stellarvue SV80ST. Will the 1000 Oaks TH-4250 fit snug with the felt shims? The SV80ST dew shield has an Outside Diameter of 104mm. The Inside Diameter of the TH-4250 is 108mm. Just double checking.
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