Baader Filters Ultra-Narrowband SII CMOS 50.4mm

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

It proves effective for capturing the essence of most emission nebulae, planetary nebulae, and supernova remnants.

For those aiming to replicate the striking imagery reminiscent of the Hubble Space Telescope (HST), such as the iconic “Pillars of Creation” in the Eagle Nebula (Messier 16), the next essential addition to your filter arsenal after H-alpha and OIII is the SII (es-two) or sulfur filter. Like H-alpha, the SII filter operates as a deep red filter near 672 nm. Combining H-alpha, OIII, and SII filters contributes to achieving that signature Hubble-like appearance for many emission nebulae. Moreover, conducting tri-color narrowband imaging with these three filters remains feasible even with the presence of the moon, ensuring your equipment remains active.

Specifications:

Capacity:

Central Wavelength: 671.7 nm

Half-value Width: 4 nm

Frame: Ring

Mount Material: Aluminium

Coating of Optical System: Reflex-Blocker™

Suitable for apertures ranging from f/10 to f/3.5

Filter Thickness: 2 mm

Filter Size: 50.4 mm

General:

Type: Filters

Type of Build: Line filter

Series: Ultra-Narrowband

Area of Application:

Useful for Photographs: Yes

Visually Useful: No

Twin Stars: No

Moon & Planets: No

Nebulae & Galaxies: Yes