As many celestial objects; such as nebulae radiate at other wavelengths; a considerable increase in contrast can be achieved by this; the background sky appears darker and all at once; faint details become visible
Can be used at both light-polluted and dark sky sites; blocks the light from mercury and sodium-vapour lamps
1.25 inch filter thread; each Astromania Ultra High Contrast Filter is individually inspected and proudly inscribed with the percentage of light transmittance of the O-III and H-beta emission lines
1.25 inch 9mm plossl eyepiece set; gives the widest viewing field along with extra sharpness and long eye relief
4-element plossl design; has a approx 42 degree AFOV; perfect for broad field lunar observations; medium sized star clusters; and a wide range of cloudy nebulas and deep-sky targets