These contrast-enhancing anodized aluminium, optical glass filters are designed to block out the wavelengths of light emitted by mercury-vapour light and other common causes of light pollution, whilst providing higher transmission at critical hydrogen-alpha and hydrogen-beta lines than competing filters.
Comprises 4 x high quality glass colour filters. Yellow, Red, Green & Moon/Neutral Density Filters included. These filters will fit most internally-threaded eyepiece barrels of 1.25"/31.7mm format. Supplied in attractive foam-lined plastic screw top storage case.
These high quality anodized aluminium, optical glass variable polarising filters reduce the amount of light entering your eyepiece. You can progressively dim the view when observing a bright object, such as the Moon or certain planets
This high performance CCD filter transmits only the Hydogen Beta emission line, and therefore is useful for greatly increasing the contrast of objects that glow in the corresponding region of the spectrum, for example the Horsehead, Cocoon and California nebulae.
This 1.25in filter consists of two joined polarized filters that provide continuously from about 2% to 40% as the rotating filter is adjusted. Great for lunar viewing without ruining your dark adaptation from staring at a bright image.