H-beta filters are also useful for imaging nebulae and objects rich in ionized hydrogen. At 486.1nm, a narrow-band filter is required to separate H-beta from nearby blue and green spectral lines. Although weaker than the H-alpha line, this is often used for visual detection as the longer red wavelengths of H-alpha are difficult to detect by eye.
- Durable sputtered coatings
- Thickness: 3.0mm
- Filters designed for use with CCD and for f/4.0 or slower
- Transmitted wavefront better than 0.25 waves/inch
- Made in America