SV115 Telescope Filter O-III Filter Narrowband Cuts Light Pollution Filter for Astronomy Telescope (1.25 inch)

OverviewNarrowband OIII filter is designed for nebula observation allowing 18nm bandwidth of light centered on a wavelength of 500nm through,
which corresponds to OIII emission lines, and reducing the transmission of certain wavelengths of light, specifically those produced by artificial light including mercury vapor,
and both high and low pressure sodium vapor lights and the unwanted natural light caused by neutral oxygen emission in our atmosphere (i.e. skyglow).

Features:
Filter substrate is fine-optically polished to 1/4 wave and <30 parallelism over both surfaces.

Suitable for visual observation on most emission nebulae, planetary nebulae and supernova remnants.

Suitable for viewing on bright nebulae like M42 Orion Nebula in heavy light pollution.

Use with a large aperture telescope under clear and dark viewing conditions with good seeing.

Narrowband filter do not eliminate the effects of light pollution or increase the object’s brightness. In many cases,
they increase the contrast between nebula and night sky, not brightening the nebula.

Thin metal cells have a clear aperture of 26mm for 1.25" filters

Each filter comes with a plastic case with high pressure EVA case lining

Specification:
Blocking area: 400-700nm
Transmittance: 90% at 495.9nm and 500.7nm
FWHM: 18±2nm
Thickness: 1.85mm
Surface quality: 60/40 (Refer to MIL-O-13830)
Diameter: 1.25 inch

WARNING:
The filters are not designed for sun observation. DO NOT LOOK AT THE SUN WITH this FILTER. You would be BLIND if you fail to observe the warning.

Package Includes:
1 x SV115 O-III 1.25" filter