DayStar Calcium H and K Line Filters

DayStar is proud to offer both Calcium H ( 3969Å ) and Calcium K line (3933.7Å ) filtering systems. Traditionally, university research has employed the Calcium K line for studies of Calcium on the Sun. These studies have been instrumental in determining depth of the solar atmosphere. Calcium offers TWO strong absorption lines at 393.3nm and at 396.9nm, known as the K and H lines. Researchers traditionally avoided the Calcium H line for academic research, as it is very close to the Hydrogen Epsilon line. The H line for visual observations, is much closer to the visual spectrum and easier to see in high contrast violet color. For purposes of clarity in isolating Calcium, Calcium K has to date been the target of choice in Calcium filters for academic research.

Unfortunately the visual spectrum ends at approximately 400nm. The further we venture below this wavelength, the more difficult it is for observers to visually see the image. Many observers simply cannot see the Calcium K line. The Calcium H line is much closer to the visual spectrum and easier to see in high contrast violet color. This makes the Calcium K line preferable for visual observation. Some observatories, such as the Dutch Open Telescope, have been imaging in Calcium H line with outstanding results.

DayStar Calcium H Line 5 Angstrom Filter

The Calcium H line is much closer to the visual spectrum and easier to see in high contrast violet color. This makes the Calcium K line preferable for visual observation.

$4,000.00

DayStar Calcium K Line 2 Angstrom Filter

University research has employed the Calcium K line for studies determining depth of the solar atmosphere. Researchers traditionally avoided the Calcium H line for academic research, as it is very close to the Hydrogen Epsilon line.

$5,800.00

Note: Calcium H and K-line filters do not require F/30 configurations. They may be used at F/15 or F/20. They also do not use the same RED or Yellow glass Energy Rejection Pre-filter. Rather, we recommend dielectric "hot mirror" UV/IR cut filters introduced prior to focus. Additionally, we suggest an additional neutral density solar film on apertures above 150mm or for long-term dedicated applications.