Baader Filters SII CMOS f/2 Highspeed 31mm

SII Filter: The narrowband S-II 7nm filter selectively allows light at a 672nm wavelength with a bandpass of 3nm, specifically crafted for nebula photography.

It proves effective for a wide range of celestial phenomena, including most emission nebulae, planetary nebulae, and supernova remnants.

For those aiming to replicate the iconic aesthetic of Hubble Space Telescope (HST) images, such as the renowned "Pillars of Creation" in the Eagle Nebula (Messier 16), the SII (es-two) or sulfur filter becomes a crucial addition to your arsenal after H-alpha and OIII. Similar to H-alpha, the SII filter operates in the deep red spectrum near 672 nm. Together, H-alpha, OIII, and SII filters yield the distinctive Hubble-like appearance for many emission nebulae. Notably, employing these three filters in tri-color narrowband imaging allows for continued astrophotography even during moonlit nights, ensuring optimal utilization of your equipment.

Specifications:

Capacity:

Central Wavelength: 671.7 nm

Half-value Width: 6.5 nm

Frame: Ring

Mount Material: Aluminum

Coating of Optical System: Reflex-Blocker™

Suitable for apertures ranging from f/3.4 to f/1.8

Filter Thickness: 2 mm

Filter Size: 31 mm

General:

Type: Filters

Type of Build: Line filter

Series: f/2 Highspeed

Area of Application:

Useful for Photographs: Yes

Visually Useful: No

Twin Stars: No

Moon & Planets: No

Nebulae & Galaxies: Yes