Daystar Quantum Sodium D Solar Filter - 0.4Å PE Grade

0.4Å PE Quantum Solar Filter, Sodium D line. For use with refractors, SCTs, Maksutovs. Includes front and rear plates, power supply, instructions, and hard case. Requires UV/IR cut filter, plus Powermate barlow or stop down mask to reach F/27-F/35 focal ratio for best performance (sold separately).

DayStar is proud to offer Sodium Na- D line (5895.9Å ) filtering systems. For visual and photographic studies. Sodium filter assemblies are designed for sub-angstrom observations with single-cavity design. Sodium lines are very narrow, but very bright. A very narrow filter of < 0.5Å is necessary to properly isolate the line from the continuum. The resulting image depicts high detail in granulation, supergranulation and P-modes.

University series filters are designed to operate unheated on the lower of the two Na D emission lines; and can be heated to accomplish transmission on the higher of the two Na D lines, making doppler studies possible by photographing in each line and derriving difference images after subtracting an average solar velocity image. This process is referred to as a dopplergram velocity image, reveals the surface motions associated with supergranulation.

These filters have until now been primarily used for research purposes only, performing doppler and supergranulation studies. Narrow bandpass Na D line filters have also been used in deep-sky observations of IO, but with significantly larger apertures.

Suitable for photographic and visual observing