MLAstro SHG 700 - High Precision Solar Spectroheliograph with Professional Optics

MLAstro SHG 700 - High Precision Solar Spectroheliograph with Professional Optics

The MLAstro SHG 700 is the modern evolution of one of the oldest and most fascinating techniques for narrowband solar observation. Originally developed in the 19th century by George Ellery Hale and Henri-Alexandre Deslandres, the spectroheliograph was perfected in 1932 by Robert R. McMath, who adapted it to record moving solar images.
Thanks to technological advances in optics, hardware and software made by Christian Buil and Valérie Desnoux, this technique has fully entered the digital era, allowing the acquisition and reconstruction of solar images using specialized software.

🔭 How the MLAstro SHG 700 works

The MLAstro SHG 700 spectroheliograph captures a thin strip of sunlight through a precision slit. That light is collimated into parallel beams and passes through a holographic diffraction grating, which scatters the visible spectrum. A focusing lens then projects the beam onto a camera sensor.
By adjusting the angle of the diffraction grating, different wavelengths can be selected to observe the Sun in different spectral lines, such as H-alpha, Sodium D, Helium D3 or Calcium K.

During the process, the telescope performs a controlled sweep of the solar disk while the system records successive image sections through the slit. Specialized software then reconstructs a complete, high-resolution solar image, revealing chromospheric details impossible to obtain with conventional filters.

⚙️ MLAstro SHG 700 kit contents

The MLAstro SHG 700 kit is delivered fully assembled and calibrated from the factory, with all the optical components necessary to start working immediately with your telescope.
To complete the installation, the following adapters may be required:

• T2 (M42) to 1.25" adapter to connect the camera to the spectroheliograph.

• Adapter 1.25" to M42 (nosepiece) to attach the SHG to the telescope's eyepiece holder.

If you already have these accessories, it is not necessary to purchase them. Otherwise, they are offered as an additional option at competitive prices.

📊 Technical specifications

75 mm MLAstro compound lenses (2 pcs.)

• Designed specifically for spectroheliographs.

• Six-element construction for flat field and superior optical performance.

• 16 mm field coverage, compatible with telescopes up to 1300 mm focal length.

2400 l/mm (25 × 25 × 6 mm) holographic diffraction grating

• Optimized for the visible spectral range.

• Caution: the coated surface is extremely delicate; avoid direct contact.

7 mm quartz slit with a 7 micron aperture

• Extremely high precision edge to minimize visual artifacts.

• Manufactured with lithographic technology for unsurpassed quality.

• Surface polished to λ/4 or better, ensuring excellent wavefront accuracy.

• Higher thermal resistance than standard glass slits, with OD7 coating for superior light blocking.

This configuration allows full solar disk sweeps with telescopes up to 730 mm focal length, providing sharp, detailed and uniform images.

🌞 In brief

The MLAstro SHG 700 combines the historical tradition of solar spectrography with today's digital innovation. It is a must-have tool for advanced astronomers and astrophotographers seeking to study the Sun with scientific accuracy and capture its activity at different wavelengths.

MLAstro SHG 700 - High Precision Solar Spectroheliograph with Professional Optics