DayStar Calcium II H-line Solar Filter
Daystar Calcium II H-line Filter
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, is much closer to the visual spectrum and easier to see in high contrast violet color. Some observatories have been imaging in Ca II H line, such as the Dutch Open Telescope image you see here with outstanding results.
* 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 Prefilter. 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.
DayStar Product Number: C2H
Until recently, these specialty filters were the domain of scientists only. Since each DayStar Calcium II H-line Filter must be individually produced, they must be pre-ordered and a minimum of 6 months must be allowed to fulfill the order. Please contact our expert sales staff for further ordering information. Thank you!
Questions & Answers
Have a Question?
Be the first to ask a question about this.