by Christian Buil

The Solar Explorer  - October 25,  2023


A set of optical component kits is available from Shelyak instruments:

You will find everything! In addition to the basic kit to build a Sol'Ex, the instrument that allows you to observe the Sun from every angle, you have Star'Ex kits to start the adventure of spectrography of stars and other galaxies!

For spectrography, you have two options, one specialized for spectral observation of the sky in high resolution (Star'Ex HR), the other specialized for low resolution spectral observation (Star'Ex BR).

The specificity of the Star'Ex HR optical kit, is to propose as standard a particular slit from which you can choose 4 distinct widths for a maximum flexibility with respect to the size of your telescope and your observational project (see the star section of this site). This is an important advance.  You even benefit from a slit only 10 microns wide to try your hand at advanced spectrography with a small telescope of only 60 to 80 mm (for example)!

The Star'Ex BR optical kit allows you to capture the entire visible spectrum in a single image. The 80 mm lens that is placed in front of the camera is upgraded for quality coverage from 390 nm to 740 nm. You will even find a "special infrared" low resolution kit, which offers a nice spectrum from 650 nm to at least 1000 nm (see examples in the Stars section of the site) - an option that will allow you to look at the spectrum of planetary atmospheres or even cold stars. The interchangeability between the visible and infrared versions is very fast, so you can multiply your sky observation field.

The table below gives an overview of the proposed optical kits (contact Shelyak for more information).

You can't print your Sol'Ex or Star'Ex in 3D... then contact Azur3DPrint - it's cheap and efficient!

Azur3DPrint (can deliver out of France):

Vincent Duch

You can register to the Sol’EX project dedicated discussion group: You will find there the latest news and an active community ready to help (French and English speaking)!

(For an English version , click here)

The YouTube channel Astro-Spectro is dedicated to Sol’Ex/Star’Ex projet. Numerous videos about Sol’Ex et Star’Ex. Do not hesitate to subscribe! 

To provide direct feedbacks (Christian Buil):, putting «solex : xxxxx» in the email title.

This site is hosted by astrosurf, which proposes also a very active (, which is the editotr of AstroSurfMagazine ( and from which you can buy dedicated books on Astronomy (

Copyright (C) 2020-2023 Christian Buil

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