This accessory from the QUARK series allows you to solar observation in the calcium-H line. Like any QUARK filter also this is simply plugged into the eyepiece of the telescope.
Please note: The sun filters QUARK calcium H-Line should (lens telescopes) are up to 150 millimeters used only in conjunction with refractors. From an opening of 80 mm, a UV / IR blocking filter should be used, which still needs to be transparent to the light of the calcium H-line, however (see "recommended accessories"). The refractor can have the front lens downstream optical elements, as in the vicinity of the focus - the name says - high temperatures that can damage these elements. So please do not flattener, Barlow or similar use.
The manufacturer recommends DayStar refractors with a focal ratio of f / 8 to f / 15, for example:
- Bresser Messier AC 90/900
- Skywatcher Evostar AC 120/1000
- Vixen A80Mf AC 80/910
With longer focal length, the image is indeed dark, but more contrast.
The two spectral calcium K (CaK) and calcium-H (CaH) are similarly important as the H-alpha line of hydrogen in the scientific Sun observation. Both calcium lines have wavelengths below 400 nanometers. Here the sensitivity of the human eye at the age declines markedly. Filter manufacturers therefore focus on the shorter wavelength CaK and recommend the purely photographic observation, since the CCD chip is sensitive enough.
The calcium-QUARK is designed to CaH-line. This has with 397 nanometer wavelength somewhat greater than the CaK-line (393nm). According to the manufacturer, this paint is still visible for most people, so that the calcium-QUARK is also suitable for visual observation.
In calcium-light watch as in H-alpha light also, the solar chromosphere. An impression conveys the image on the right. Also prominences are seen in the light of the calcium ions. Because of their low brightness but especially photographically.