Filter

DayStar Quark Mg I b2

Powered eyepiece-style solar filter with Fabry-Perot etalon

Magnesium I b2 line at 517.3nm (5172.8A)

Sub-Angstrom bandpass, under 0.5nm (about 0.4A) FWHM

Built-in

4.2x telecentric Barlow

1.25-inch snout (2-inch optional)

USB-powered

5V

For refractors f/4 to f/9

Requires a front-aperture energy-rejection filter