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Calcium II H line and K-line Filters
Images by Fred Bruenjes using 5" F/8 refractor
0.45Å Hydrogen Alpha Filter / 4X Powermate
5.0Å Calcium H line Filter / 2X Barlow
Moonglow Technologies prototype webcam
DayStar is proud to offer Calcium H ( 3969Å ) and two 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 have previously avoided the H line for academic research, as it is very close to the Hydrogen Epsilon line.  For purposes of clarity in isolating Calcium, and because imaging sensors offer similar sensitivity to the K as the H lines of Calcium, the K has to date been the target of choice in Calcium filters.  However, as 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.  The H line for visual observations, however, is much closer to the visual spectrum and much higher contrast in high contrast violet color. Some observatories have been imaging in Ca II H line, such as the Dutch Open Telescope with outstanding results.
DayStar Calcium H-line Filter assemblies*

5.0Å Single cavity visual series filter system $4000.00
suitible for amateur and University settings - for visual and photographic, indoor or outdoor observing settings.

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Images by Dutch Open Telescope 450mm telescope
Observatorio del Roque de los Muchachos • Instituto de Astrofísica de Canarias
((THESE IMAGES ARE FOR CALCIUM H LINE DEPICTION ONLY.))

DayStar Calcium K-line Filter assemblies*

2.0Å Single cavity University series filter system $4800.00
suitible for academic purposes - used indoors and/or with heliostat configuration

* Note. These systems do not require an energy rejection pre-filter for operation. Filters operate with optical systems as fast as f/20 but due to anticipated heat loads we do not recommend apertures larger than 80 mm. At this transmitted wavelength, a 80 mm. aperture delivers < 1 arc sec. resolution. The spectral uniformity and image quality delivered at the eyepiece or imaging surface is truly remarkable.

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DayStar 2.0 Å Calcuim K-line filtergrams taken with a 80mm. f/20 telescope. 

      Visually,  the incredible imaging fidelity of 8-10 Å filter is a close rendition of the above images.    

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* HALF-BANDWIDTH: The term half-bandwidth refers to an optics industry standard of measure.  On a chart depicting the peak where light is transmitted, that peak's width is measured at the point 50% between zero and full transmission. This term is called half-bandwidth.

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DayStar Filters LLC™ 149 Northwest OO Highway   Warrensburg, MO 64093 - USA
Telephone: 660-747-2100 • jen@DayStarFilters.com • FAX: 1-866-791-0448

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