Narrowband (NB) filters  enhance contrast of emission objects by accepting only a narrow range of wavelengths around the emission lines of hydrogen (H-a, 656 nm), oxygen (OIII, 501 nm), sulfur (SII, 672nm) and others.

Light pollution suppression (LPS) filters are designed to suppress the common emission lines generated by artificial lighting, yet allow the important nebula emission lines to pass, thus enhancing the contrast of astronomical objects, particularly emission nebulae.

Extremely durable coatings withstand humidity changes, extreme temperature fluxes and remain spectrally accurate in CWL and band pass adherence.

Extremely durable coatings withstand humidity changes, extreme temperature fluxes and remain spectrally accurate in CWL and band pass adherence.

Extremely durable coatings withstand humidity changes, extreme temperature fluxes and remain spectrally accurate in CWL and band pass adherence.

Extremely durable coatings withstand humidity changes, extreme temperature fluxes and remain spectrally accurate in CWL and band pass adherence.

Extremely durable coatings withstand humidity changes, extreme temperature fluxes and remain spectrally accurate in CWL and band pass adherence.

Extremely durable coatings withstand humidity changes, extreme temperature fluxes and remain spectrally accurate in CWL and band pass adherence.

The Optolong L-Pro filter delivers better color balance by maximizing transmission band, permitting you to create pictures of broadband objects with emission spectral lines.

I-Series filters are designed to approximately equalize the flux of  Interline CCD detectors (formerly Kodak), including compensation for the solar photon flux.

The Optolong Sulfur II 12nm Narrowband Filter works by allowing a 12nm bandwidth of light, centered on the 672nm wavelength through, and blocking contrast-killing light pollution wavelengths from coming through.

Improve image sharpness with the addition of an Optolong UV-IR Cut Filter, which blocks Ultraviolet and Infrared transmissions yet lets the visible spectral lines shine through. The IR (700nm to 1100nm) and UV (300nm - 400nm) part of the spectrum are not detectable to human eyes, however not to most CCD and other computerized cameras, which are sensitive to 300nm to 1100nm.

The Optolong H-Alpha 12nm Narrowband Filter works by permitting a 12nm light bandwidth, focused on the 656nm wavelength through, and hindering the transmission of contrast-killing light pollution wavelengths.

The Optolong LRGB Filter Set includes four 36mm unmounted filters, including Red, Green, Blue, and Luminance. They're suitable for de-bayered monochrome CCD and CMOS cameras, and function remarkably for both planetary and deep sky imaging.

The Optolong H-Alpha 7nm is a very narrow emission-line filter that functions by permitting a 7nm light bandwidth, focused on the 656nm wavelength through, and obstructing the transmission of contrast-killing light-pollution wavelengths.

The Astronomik SII-CCD filter is a narrow-band-filter for CCD photography.