The 10mm Blocking Filter is for use with any of the SolarMax series filters it is optimised to provide a full disc image on telescopes with a focal length up to 1000mm. It is a 1.25" right angled diagonal unit.... Learn MoreFREE SHIPPINGModel#: BF10(48 States)
Learn MoreFREE SHIPPINGModel#: BF15ST(48 States)
Coronado has been developing ultra-narrowband filters and associated technologies for the professional market for over 40 years. Experience the Sun the Coronado way in the light of Hydrogen-Alpha (Ha) and open up a whole new world of astronomy! What's so interesting about Hydrogen-Alpha? The red light of H-Alpha with a wavelength of 656.3 nm (1 nm = 1 billionth of a meter) is a very prominent feature in the solar light spectrum since hydrogen makes up 75% by weight of the outer layers of the sun. This light shows us layers up to 1700 km above the sun's visible surface and is especially important for imaging the lower chromosphere.
The bright regions around sunspots, called plages, and brilliant solar flares are easily seen at this wavelength. Filaments, vivid string-like regions, and sunspots, large blotches on the solar surface, appear dark. Filaments on the solar limb appear bright against the blackness of space and are called prominences you have probably seen the stunningly beautiful images of. The Sun is active, ever changing, and constantly entertaining. See the Sun in a new light- the Coronado way!