What are QUARK sunscreen?
Under the name QUARK the American manufacturer Daystar offers sunscreen. These have revolutionized the solar observation:
- The QUARK filters are relatively inexpensive, compared to other, to a particular spectral line toward optimized filter.
- They are easy to use: you do not need expensive Sonnenteleksop or remodeling. Just use a small refractor and plug the QUARK in the focuser between the diagonal and an eyepiece. We recommend the use of an additional UV / IR cut filter (see "recommended accessories"). This filter is easily fitted to the eyepiece.
- The QUARK filters are equipped with heating, holding on thermal expansion of the distance filter etalon constant. Thus, the operation of the filter is always guaranteed.
- There are already several models of this series: You can replace the filter as an eyepiece and thus switch between the observation in H-alpha, H calcium or sodium D light so easy.
Why the sodium D-line?
In the sodium D2 line at 589 nanometers we recognize details in fine sunspots, solar flares (Plages) and the granulation of the photosphere. Even solar flares (flares) show up in sodium light earlier than in white light.
The image is iim compared to calcium and H-alpha filter light so that the observation easier and the exposure time can be selected to be lower in photography.
Please note: This QUARK sun filter is suitable for refractors with an aperture ratio of f / 4 to f /. 8