Astronomik Filters OIII 12nm CCD T2 (43811)

Narrowband filters redefine performance and durability for imaging and research. These filters improve the contrast of emission targets by reducing background signals, ensuring a guaranteed transmittance of over 90% at the emission wavelength. This high level of transmittance delivers the strongest possible signal. Narrowband filters are especially valued for minimizing halos around bright stars, even during extended exposures of 30-45 minutes, which are typical in narrowband astrophotography. Additionally, they are coated to the edge and edge-blackened to effectively minimize stray light, which is essential for blocking most light outside the narrow bandpass.

Contrast is the key focus of narrowband filters in imaging. By reducing background noise, they reveal faint features more clearly. The narrower the filter, the greater the contrast enhancement. However, maintaining a strong signal (%T at the emission line) becomes increasingly challenging as filters become spectrally narrower. This is why the >90%T guarantee is crucial, even though it requires costly manufacturing processes. This guarantee ensures users can enjoy improved contrast compared to cheaper 7-8.5 nm filters on the market. For instance, images of the Crescent Nebula (NGC 6888) taken with progressively narrower filters demonstrate how the nebula and its faint surrounding nebulosity stand out more against the background. Recent production advancements have even increased transmittance to 97-98%T at emission wavelengths, surpassing older specifications.

Specifications

• Capacity:
  • Connection: T2 (M42 x 0.75)
  • Mount Material: Aluminium
  • Transmission: 95%
• Optical System Coating: MRF
• Frame: T2 (M42 x 0.75)
• Half-value Width (nm): 12
• General Features:
  • Type: Line filter
  • Series: OIII 12nm
• Area of Application:
  • Useful for photographs: Yes
  • Anti light-pollution: Yes
  • Galaxies and star clusters: Yes
  • Planetary nebulae: Yes
  • Supernova remains: Yes
  • Hydrogen nebulae: Yes