Svbony SV227 SHO 5nm 1.25" Filter Set SII H-Alpha OIII Narrowband Filters for Deep Sky - W9187A

• The Narrowband OIII 5nm filter is designed for nebula observation allowing 5nm bandwidth of light centered on a wavelength of 500.7nm through, and reducing the transmission of certain wavelengths of light, specifically those produced by artificial light including mercury vapor, high- and low-pressure sodium vapor lights and the natural light caused by neutral oxygen emission;
• The H-Alpha 5nm is an extremely narrow emission-line filter that works by allowing a 5nm bandwidth of light, centered on the 656nm wavelength through, and blocking the transmission of contrast-killing light pollution wavelengths;
• The SII 6.5nm Extra Narrowband Filter transmits a 5nm bandwidth of light that is centered at 672nm and drastically reduces other transmissions, including wavelengths of light that are responsible for light pollution. Due to the narrow bandwidth and high transmission rate of this filter, you will experience a major boost to contrast;
• The Blocks infrared wavelengths from 700nm to 1100nm so you don't need a separate IR-Cut filter, suitable for used for deep sky photographic and all are NOT for use on the Sun; 90% transmission of the filters can block the light from mercury and sodium vapour lamps; Standard M28.5x0.6 thread interface, can de directly into the 1.25 inch barrel of your telescope eyepiece.

Feature

1. Optical high precision double sided polishing to ensure that the parallelism is higher than 30 inch and high flatness 1/4λ; to ensure that does not affect the image quality
2. Precision double sided optical coating; non two piece glue; effectively improve the transmittance and cut off depth
3. 300-1000nm wavelength range; Oxygen III 5nm extra narrowband filter transmits a 5nm bandwidth of light that is centered at 500.7nm
4. Standard 1.25 inch interface; thin metal cells have a clear aperture of 26mm for 1.25 inch filters
5. 300-1000nm wavelength range; the Sulfur II 5nm extra narrowband filter transmits a 5nm bandwidth of light that is centered at 671.6nm

Cut-off Depth ≥OD5

With a Cut-off Depth ≥OD5, the SV227 1.25 inch narrowband filter set can effectively block unwanted light, ensuring pure and clear stargazing.

Package Includes

1.25-inch H-alpha Filter x1
1.25-inch SII Filter x1
1.25-inch OIII Filter x1
PP Storage Cases x3