Astronomical Filter Photographic Narrowband 1.25 Inch For Deep Sky

Description

Astronomical Filter Photographic Narrowband 1.25 Inch For Deep Sky
The Sulfur II 7nm Extra Narrowband Filter transmits a 7nm bandwidth of light that is centered at 672nm and drastically reduces other transmissions, including wavelengths of light that are responsible for light pollution (both artificial and natural).
And this SII filter also blocks infrared wavelengths from 300nm to 1000nm so you don't need a separate IR-Cut filter.
Filter Substrate
The 1.25" Filter is made of glass import from Germany that has been multi-coated with an ion-assisted deposition technology to ensure scratch resistance and stability on the central wavelength, or CWL.
Filter Cell
The filter cell is made of lightweight, strong metal and is CNC machined, sand-blasted; black anodized, and then laser engraved. The result is a super thin filter cell that will produce a clear aperture of 26mm.
Narrow band for synthesizing the "Hubble Image"
Generally, the image processed by this three narrow bands: HA, SII, OIII, is known as “Hubble Image”. The processing method is the synthesis of RGB: SII= red, HA = green, OIII= blue, such as the famous "Pillars of Creation" (M16 Eagle Nebula).
Specification:
Size: 1.25Inch
Filter Type: SII Filter
CWL: 500.7nm
FWHM: 7nm
T peak: 80%
Substrate: B270
Substrate Thickness: 1.85mm
Wavelength Range: 300-1000nm
Blocking: OD3 @300-1000nm
Clear Aperture: 26mm
Surface Quality: 60/40
Parallelism: 30"