{"product_id":"filtro-pro-veil-h-alpha-7nm-2","title":"Pro Veil H-Alpha 7nm 2'' Filter","description":"\u003cdiv\u003e\n\u003cp\u003e\u003cb\u003eHidden in the light: the colours of the emission nebula\u003c\/b\u003e\u003c\/p\u003e\n\u003cp\u003eIn and around human settlements, there are a lot of lights. This illumination not only helps people find their way in the dark, but also illuminates the sky. Faint celestial objects disappear, hidden by the artificial brightness of the sky.\u003c\/p\u003e\n\u003cp\u003eUnlike stellar objects such as globular clusters and galaxies, or reflection nebulae such as the blue glow around the Pleiades, emission nebulae emit their light in very specific colours. The brightest of these so-called emission lines are\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eH-alpha: 656.3 nm\u003c\/li\u003e\n\u003cli\u003eH-beta: 486.1 nm\u003c\/li\u003e\n\u003cli\u003eO-III_1: 495.9 nm\u003c\/li\u003e\n\u003cli\u003eO-III_2: 500.7 nm\u003c\/li\u003e\n\u003cli\u003eS-II_1: 671.7 nm\u003c\/li\u003e\n\u003cli\u003eS-II_2: 673.1 nm\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eWhile only the O-III and H-beta lines can be distinguished with the naked eye due to the human eye's poor red sensitivity, a camera can capture all the colours.\u003c\/p\u003e\n\u003cp\u003eHigh-performance nebula filters, such as the Omegon Veil nebula filters, suppress artificial lighting but let the colours of the nebulae pass through. This way, faint emission nebulae such as the Cirrus Nebula or the North America Nebula can also be observed outside the desert or high mountains.\u003c\/p\u003e\n\u003cp\u003e\u003cb\u003eH-alpha filter:\u003c\/b\u003e This narrowband nebula filter only lets red light with a wavelength of 656 nanometers pass through, which is the line where HII regions (hydrogen nebulae) are seen.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"Omegon","offers":[{"title":"Default Title","offer_id":53581587251543,"sku":"82009","price":211.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0552\/6198\/6860\/files\/82009_1.jpg?v=1779016107","url":"https:\/\/astrotelescopios.com\/en-uk\/products\/filtro-pro-veil-h-alpha-7nm-2","provider":"Astro Telescopios","version":"1.0","type":"link"}