MLAstro SHG (Housing only)

Starting September 11, 2025, the Housing-only kit will no longer be offered publicly. Too many first-time Sol’Ex users ran into difficulties assembling the 3D-printed kits, and we’ve decided to simplify things.

If you’re an experienced Sol’Ex builder and you’re absolutely confident you can make it work on your own, send me an email at trong.minh@mlastro.com and I’ll make the Housing-only option available to you directly.

Thanks!

Check out our Optical kit to go with your SHG housing here. Please note that if you add the SHG separately you'll have to assemble and calibrate the housing yourself. If you want a fully calibrated SHG with Optics included out of the box then check out our prebuilt kits.

This Housing kit is 100% compatible with Shelyak's SolEx Optical kit (ES0029), The Star'Ex HR and LR optical kit (requires the additional Guide kit)

If you want the Guide kit to use your MLAstro SHG as a high-resolution stellar spectrograph the please add the Guide kit separately.

**Important Information for Beginners**

If you are just starting out with an SHG, please note: This device is strictly for imaging only; it cannot be used visually. The SHG functions as a "scanner," capturing a snippet of the Sun's spectrum and, with the help of computer software, turning that scanning video into an image. With this device, you can observe the Sun in multiple wavelengths (e.g., CaK, CaH, Ha, Hb, Sodium, He D3), and the image uniformity and contrast are superior to most amateur-grade etalon filters.

Since you cannot do lucky imaging with it, the SHG works best with small aperture, short focal length scopes to provide full disk images. The longest recommended focal length for an SHG is about 1000mm (if you use scope longer than that, it'll simply crop the Sun and you will not get full disk in 1 scan); beyond that, seeing conditions will limit resolution. If you're looking for a visual scope, this is not for you.

For those unfamiliar with how this device works, please watch this [instructional video]. It details how the device works, how to set up, focus, capture, and process the "scan" into images.

For more information, read this comprehensive guide by Christian Buil, the father of Sol'Ex/Star'Ex, from which our SHG product is derived: [Sol'Ex Presentation](http://www.astrosurf.com/solex/sol-ex-presentation-en.html). The SHG is quite different from any device you may have used before, so it's crucial to invest time and effort into learning how it operates before making a purchase.

**MLAstro's SHG Platform**

Our SHG platform is designed to provide the ultimate SHG experience. If you already have your Sol'Ex/Star'Ex optical kits, you can use them with our SHG aluminum kit, which is 100% compatible with Shelyak's optical kits. If you want advanced optics then please check out the Optics section.

Mechanical advantages:

1. High Rigidity and Thermal Stability: 3D printed housings can degrade when exposed to prolonged heat and solar radiation. They may deform and shift under intense heat, making focus/collimation challenging, especially in remote setups. Our SHG, made from aluminum with some 3D printed parts, offers superior rigidity, durability, and thermal stability, ensuring that your focus/collimation remains stable regardless of exposure time. This is crucial for remote imaging rigs. MLAstro SHG features a breakthrough "unibody" design where the mainframe is CNC-machined from a single piece of aluminum. This ensures high rigidity while maintaining a lightweight build. The entire setup, including optics and camera, weighs less than a kilogram, only about 30% heavier than the 3D printed counterpart.

2. High Precision Optical Alignment: The tight tolerance and well-designed moving mechanism of our aluminum SHG help maintain good squareness and centricity of the optical alignment. Built-in mechanisms allow for perfect optical alignment when needed, ensuring the best possible image quality.

3. Multiple Optical Designs/Sizes: Through a clever 3D printed sleeve system, the MLAstro SHG platform supports lenses up to 35mm in diameter and focal lengths up to 110mm on the collimator and 200mm on the camera (up 135 mm on the collimator if you are willing to print the lens sleeve yourself). It can also host gratings up to 40mm wide and 6mm thick (let me know in the order special request that you want this, otherwise the housing is shipped with standard 25x25x6mm grating mount), with slits up to 12mm. This versatility opens up endless possibilities.

4. Micrometers on the Lens and Grating Dial: Micrometers are a significant upgrade over the old focusing mechanism of 3D printed designs. They help you focus the lens easily while ensuring the spectral spread is centered when the grating rotates. If you've used a 3D printed SHG, you'll appreciate this improvement. The micrometer on the camera lens eliminates the need for backlash and flexure-prone helical focusers.

5. Complete Build Solution: Assembling and calibrating an SHG can be challenging for new users. Finding compatible optics can also be problematic. That's why we offer a prebuilt/calibrated MLAstro SHG Kit with everything included and ready to be installed on your telescope, allowing you to start imaging right away without the hassle of assembly and calibration.