Optolong OIII Filter 3nm 2 inch

Optolong OIII Filter 3nm 2 inch: a single emission line, maximally isolated

This filter isolates the OIII emission line around 500.7 nm with a half-width of 3 nm. All other light, including streetlights and moonlight, is blocked. This results in a deep dark sky background, maximizing the visibility of nebula structures at this wavelength. At 3 nm, this is Optolong's narrowest OIII version for maximum contrast.

Narrowband filters are the foundation of monochrome camera photography: you photograph the lines separately and combine them into color composites, such as the well-known Hubble Palette (SHO).

What you use this filter for

Designed for planetary nebulae, supernova remnants like the Veil Nebula, and oxygen-rich parts of emission nebulae. Because light pollution is virtually completely blocked, you can also photograph from the city and in moonlight with this.

Technology

The Schott glass is finely optically polished and features multi-layer ion-assisted coatings: high transmission in the passband, strong blocking outside of it, and a central wavelength that remains stable with temperature changes. The thin metal mount minimizes vignetting.

Featured accessories

Combine this filter with the other lines (H-alpha, OIII, and SII) for complete narrowband composites. A bright focus filter speeds up focusing.

For whom yes and for whom no

• Astrophotographers with a monochrome camera and filter wheel
• ✓ For those who want to photograph under a light-polluted sky or by moonlight
• Owners of color cameras: a dual-band filter like the L-eXtreme is more practical for those.

Specifications

You can find more accessories for this merk at the Optolong merk page.