Thousand Oaks Optical Oxygen III Filter - 1.25" # LP-325

Our #: OFIL-TO-LP325
Mfg #: LP-325
Sale Price: $79.95 Our Price: $89.00
Free shipping for this item in the US
More Info

Contiguous US Customers:
All items we sell ship for free within the Contiguous US. Shipping will be via the cheapest shipping method which will vary depending on the items in your order. During checkout, you may also be shown other optional faster shipping choices.

US Customers in Hawaii and Alaska:
Free shipping applies to almost all products. A few large telescopes and mounts are excluded from this free shipping offer. For these items, please contact us to obtain a shipping quote before you check out using the online shopping cart.

International Customers:
Free shipping does not apply to international orders. During check-out, you will be presented with several shipping choices and costs. However, the export of some items may be restricted outside the US due to size or manufacturer restrictions.

Out of Stock
Availability: No ETA available from the manufacturer at this time

Please note: Thousand Oaks' filters often have tiny dots, sleeks, and/or light scratches on the glass surface. These flaws will have no impact on optical performance and the spectral characteristics of the filter are not compromised. These are all brand new as received from the manufacturer and this is just how they come.

Quick Overview

  • Provides light pollution rejection when viewing diffuse, emission, and planetary nebulae
  • Passes 93% of the light emitted by these object types
  • Very narrow bandpass on just the ~496nm and ~501nm spectral emission lines
  • Improves nebular clarity and contrast

Product Details

Oxygen III (OIII) filters are sometimes referred to as light pollution rejection (LPR) filters but their effect goes beyond the reduction of light pollution alone. This OIII filter is a bandpass filter that allows only a small portion of light in the visual doubly-ionized O-III portion of the light spectrum to be passed through the filter glass.

This filter will pass only a very small emission line centered at the ~496nm and ~501nm OIII lines. This is 93% of the spectrum of light usually emitted by diffuse, emission, and planetary nebulae. By rejecting most other light certain nebula will appear more clearly with sharper contrast against a blacker sky.

Other Information

  • Country of Manufacture: United States