Astronomik Filters OIII Filter SC-Frame (43774)

Narrowband filters set a new standard for performance and durability in imaging and research. They are designed to enhance the contrast of emission targets by effectively reducing background signals. With a guaranteed >90% transmittance at the emission wavelength, these filters provide the highest possible signal for astrophotography. Narrowband filters are particularly known for minimizing halos around bright stars, even during long exposures of 30-45 minutes, which are common in narrowband imaging. Additionally, these filters are coated to the edge and edge-blackened, which is essential for minimizing stray light while blocking most light outside the narrow bandpass.

Contrast is the key to 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) becomes challenging as the filter narrows. This is why the >90%T guarantee is crucial, even though it increases manufacturing costs. Narrower filters provide significantly better contrast compared to less expensive 7-8.5nm filters on the market. For example, in images of the Crescent Nebula (NGC 6888) taken under identical conditions, narrower bandwidths make the nebula and its faint surrounding nebulosity stand out more prominently from the background. Recent advancements in production technology have further improved transmittance to 97-98% at emission wavelengths.

Specifications:

• Half-value width: 120
• Frame: SC thread
• Mount material: Aluminium

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

Applications:
It is useful for photography, effective against light pollution, and visually beneficial for observing celestial objects.