Astronomik Filters OIII 12nm CCD 1.25" (20600)

Narrowband filters set a new standard for performance and durability in imaging and research. They enhance the contrast of emission targets by reducing background signals, ensuring that faint structures in nebulae stand out more prominently. With a guaranteed >90% transmittance at the emission wavelength, these filters provide the highest signal possible. They are especially effective at minimizing halos around bright stars, even during long exposures of 30-45 minutes, which are typical for narrowband imaging in astrophotography. Additionally, these filters are coated to the edge and edge-blackened, a critical feature for minimizing stray light while blocking most light outside the narrow bandpass.

Contrast is key in narrowband imaging, as it highlights faint features by suppressing background noise. The narrower the filter, the better the contrast. However, maintaining a high signal (%T at the emission line) as the filter narrows is challenging and costly to manufacture. This is why the >90%T guarantee is so important. It ensures you can achieve improved contrast with narrower filters compared to cheaper 7-8.5nm alternatives. For example, images of the Crescent Nebula (NGC 6888) taken under identical conditions show how narrower bandwidths make the nebula and its faint surrounding nebulosity "pop" against the background. Recent advancements in production technology have further improved transmittance to 97-98% at emission wavelengths.

Specifications:

• Coating: Multiple coatings
• Mount material: Aluminium
• Connection: 1.25"
• Frame size: 1.25"

General Information:
This filter belongs to the OIII 12nm series and is a line filter designed for various applications.

Applications:
It is highly effective for photography, visual observation, anti-light pollution purposes, and even daylight or twilight observation.