About this product
Part Number: 2 Light Pollution Filter
Astro Essentials Light Pollution Filter 1.25" / 2"
This contrast-enhancing anodised aluminium filter with optical glass is designed to block wavelengths of light emitted by mercury-vapour lights and other common causes of light pollution whilst providing higher transmission at critical hydrogen-alpha and hydrogen-beta lines than competing filters.
Bright, light-polluted skies appear darker, and the contrast between object and sky is improved significantly. This contrast-enhancement effect is particularly apparent when viewing nebulae. Unlike stars, emission nebulae give off light in a very narrow range of wavelengths. The filter allows maximum transmission of the important wavelengths of H-alpha, H-beta and doubly ionised oxygen – the ones most commonly emitted by nebulae.
Galaxies and star clusters are also enhanced but to a lesser degree. It also enhances reddish planetary detail.
Works well in telescopes of all apertures.
Available in two sizes, threaded to fit either standard 1.25” or 2” astronomical eyepieces.
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