• The Spectroheliograph is a foundational tool for narrowband solar analysis, originally developed in the 1890s by George Ellery Hale and Henri-Alexandre Deslandres for advanced solar research.
• In 1932, Robert R. McMath enhanced the technique by introducing motion-picture capabilities, laying the groundwork for modern solar imaging.
• Today’s digital spectroheliograph systems, such as the MLAstro SHG700, are used to capture high-resolution solar images in specific spectral lines.
• Unlike Etalons, which are fixed-bandpass filters used for imaging the Sun at a single wavelength (e.g., H-alpha), spectroheliographs use slits which are more customizable for various spectral lines.

The Spectroheliograph is foundational narrowband analysis framework that was developed by George Ellery Hale and Henri-Alexandre Deslandres in the 1890s for extraordinary solar research. In 1932, Robert R. McMath took the science of spectroheliography to a new level and with modern day systems, the solar devices is now used for image capture of the sun as well.

Unlike a more traditional solar filter such as an Etalon which generally images the Sun at a fixed bandpass or wavelength, spectroheliographs such as the MLAstro SHG700 use slits which are typical in spectroscopy and can be customized by tuning different spectral lines. When sunlight goes through a collimator, it transforms into parallel rays which result in diffraction grating, thus dispersing wavelengths that can be beamed onto a camera sensor and captured.

When using spectroheliographs, typically a high frame rate is used at centered spectral line and recorded as such.

A spectroheliograph is only used for imaging purposes, it should NEVER be used visually as it is unsafe.