Omegon OIII Nebula Filter 1.25 inch

Omegon OIII nebula filter 1.25 inch: the sharpest contrast on planetary nebulae

This specialized narrow-band filter is intended for observers who want to get the maximum detail out of planetary nebulae and supernova remnants.

Two wavelengths, nothing more

The filter transmits almost exclusively light around 496 and 501 nanometers, precisely the emission lines of doubly ionized oxygen. Those lines dominate in objects such as the Veil Nebula, the Ring Nebula, and the Dumbbell Nebula.

What you see through it

Because all other wavelengths are blocked, including street lighting, moonlight, and a large portion of starlight, the contrast between the object and the background becomes much greater. Filaments, edges, and gas structures emerge that are barely distinguishable without a filter.

Featured accessories

The filter blocks a lot of light, so the effect is strongest from an aperture of approximately 150 mm. On smaller telescopes it only works at low magnification.

For whom yes and for whom no

• ✓ Observers of planetary nebulae and supernova remnants
• ✓ Telescopes from approx. 150 mm aperture
• ✓ Anyone who already has a broadband filter and wants to filter more selectively
• ✗ Small telescopes under 150 mm: the image quickly becomes too dark
• ✗ Observation of galaxies and star clusters: they do not emit in OIII

Specifications

You can find more accessories for this brand at the Omegon brand page.