Optolong SHO Filter Kit 2"

Narrowband filters increase contrast by allowing only a certain range of light wavelengths corresponding to specific spectral lines to pass through, for example, Hydrogen (H-a, 656nm), Oxygen (OIII, 501nm), Sulfur (SII, 672nm), etc. The filters can always be used for photography, even when the Moon is visible, or as a light pollution filter in the city. The exposure time duration is not critical: you can also take long-exposure photographs. OIII filter: the narrowband nebula filter allows light at 500 nanometers to pass. This is the doubly ionized oxygen line. Planetary nebulae and supernova remnants glow in this color. H-alpha filter: this narrowband nebula filter allows red light with a wavelength of 656 nanometers to pass. This is the line at which HII regions (hydrogen nebulae) shine. SII filter: the narrowband filter allows light from ionized sulfur atoms at 672 nanometers to pass. This is the line at which many planetary nebulae, emission nebulae, and supernova remnants shine.

Main features

Optolong quality for a reliable and satisfying observation experience.

• Type: Filter
• Connection: 2"
• Frame: 2"
• Frame material: Aluminum
• Optics coating: multi-layer (plane-parallel)
• Connection (telescope side): 2"

Main technical specifications