Optolong 2" LRGB and 7nm H-alpha Filter Set
Optolong 2” LRGB and H-alpha 7nm Filter Set
This Optolong 2” LRGB and H-alpha 7nm Filter Set is made with Schott glass that has been multi-coated with an ion-assisted deposition technology to ensure scratch resistance and stability on the central wavelength, or CWL. 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 45mm.
LRGB Filter Set
The Optolong LRGB Filter Set comes four 2” mounted filters, including Red, Green, Blue, and Luminance. They are designed for de-bayered monochrome CCD and CMOS cameras, and work great for both planetary and deep-sky imaging. Like all Optolong filters that are designated as “CCD”, this filter set blocks infrared wavelengths from 700nm to 1100nm so you don't need a separate IR-Cut filter. The transmission of each filter is designed for maximum contrast and beautiful results. There is a gap between the green and red filters that improves color balance and separation by blocking out the Sodium line at 589nm. Also, OIII emission is allowed to overlap on the blue and green filters for more natural color.
H-alpha 7 nm Filter
The Optolong H-alpha 7nm is an extremely narrow emission-line filter that works by allowing a 7nm bandwidth of light, centered on the 656nm wavelength through, and blocking the transmission of contrast-killing light pollution wavelengths. Wavelengths that are responsible for natural light pollution, or skyglow, are drastically reduced, as is artificial light pollution caused by high and low pressure sodium vapor and mercury vapor lights. The result is a high contrast image that reveals the H-alpha line in all its glory. This Optolong H-alpha 2” filter will provide the ultimate in contrast between the skyglow background and H-alpha emitting objects, but because it has a FWHM of just 7nm, you won’t see as many stars in the final image as you would with the Optolong 12nm H-Alpha Filter. Use this filter alone for CCD or DSLR imaging, or use together with OIII 6.5nm and SII 6.5nm filters to get a tricolor image of gaseous nebula from light polluted skies. Like all Optolong filters that are designated as “CCD”, this H-alpha filter also blocks infrared wavelengths from 700nm to 1100nm so you don't need a separate IR-Cut filter.