Daystar Filters designed this version of the QUARK H-Alpha Eyepiece Solar Filter specifically for viewing prominences. Prominences, a detail of the chromosphere projected against the blackness of space behind the sun, are seen with improved contrast due to the filter's narrower bandpass versus a wider bandpass filter tuned for conventional chromosphere surface viewing.
This all-in-one hydrogen-alpha filter is engineered to eliminate unnecessary components which reduced the size and weight, and enabled it to fit in a compact form factor that simply inserts into 1.25" or 2" diagonals and accepts 1.25" eyepieces. This design enables the use of nighttime telescopes for solar viewing. In addition to the tunable H-alpha filter, the Quark also functions as a 4.3x Barlow lens, with a 2-element lens system designed to be telecentric which flattens the field of view and reduces parallax, and optical coatings that are optimized for the 656nm H-alpha wavelength.
While there are no OTA aperture limitations, Daystar recommends the use of UV/IR cut filters or front-mount energy rejection filters on OTAs over 80mm of for long-duration solar viewing sessions. For best results, they suggest using refractor-style scopes with focal ratios between f/4-f/8, and you can enjoy full-disk viewing with focal lengths up to 450mm. The filter is powered via a micro-USB port, and Daystar includes a power cord and an AC adapter to meet the high-power requirements of 5 VDC 1.5A. To enable its use at home and abroad, a set of international outlet plugs is provided with adapters for the US, UK, EU, and Australia.