Démarrage du projet Sol'Ex

Solar/Stellar spectroscope developed by Christian Buil
Christian Buil
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Démarrage du projet Sol'Ex

Post by Christian Buil »

Sol'Ex (pour Solar Explorer) est un petit instrument que j'ai conçu avec l'idée d''être réalisé en impression 3D et avec un minimum de moyens dans le but d'observer l'atmosphère solaire dans la raie de l'Hydrogène, mais aussi toute autre raie de votre choix. Comme il se doit ici, il s'agit d'un spectrographe, plus particulièrement d'un spectrohéliographe.

Image

Les choses se concrétisent à présent. D'abord un site existe, qui détaille les raisons du projet, comment fabriquer l'instrument, le réglet et comment l'utiliser. Voir ici :

http://www.astrosurf.com/solex/

Bien sûr, pour arriver au bout de cette réalisation il faut que par un moyen ou un autre, vous puissiez réaliser des petites pièces en impression 3D, soit car vous possédez une imprimante, soit, en passant par des amis, les membres d'un club, votre entreprise, un FabLab local, etc. Vous pouvez télécharger depuis le site Solex l'ensemble des fichiers nécessaires. Aujourd'hui, il n'y pas d'autre moyen, car il n'existe pas un kit des pièces mécaniques. Un peu d'huile de coude va être nécessaire (c'est aussi l'occasion d'apprendre) !

En revanche, un kit des pièces optiques nécessaires existe, ce qui va considérablement faciliter votre tâche si vous voulez vous lancer. Ce kit comprend une fente haute performance de 10 microns, un ensemble de deux objectifs que j'ai calculés spécialement pour le projet Sol'Ex et fabriqués spécifiquement (j'ai inclus des verres spéciaux dans la formule pour une performance maximale), un réseau à diffraction de 2400 traits/mm.

Il vous en coûtera un peu moins de 400 euros TTC (hors frais d'envoi). Vous trouverez un lien vers une fiche produit de la société Shelyak Instruments sur le site Solex. Vous bénéficiez jusqu'au 28 février 2021 de ce tarif préférentiel dans le cadre d'une souscription.

Je suis conscient que cela peu représenter une somme assez élevée pour un équipement à construire soi-même (sachez que le maximum a été fait pour abaisser au mieux le coût), mais j'espère que la lecture du site vous démontrera que ladite somme sera vite rentabilisée. On peut même envisager de faire bien plus que de l'imagerie solaire, vous le verrez sur le site avec une section consacrée à l'observation des étoiles !

Un certain nombre d'entre vous ont déjà manifesté leur intérêt, ne traînez pas trop.

Enfin, notez qu'aura lieu le samedi 30 janvier à 18h un atelier ZOOM organisé par Shelyak sous forme d'une présentation et d'un jeu de questions/réponses en complément de ce que vous trouvez sur le site. N'hésitez pas à vous inscrire. Voici le lien :

https://framadate.org/qoRqYwG8fZ6aQLeA

Bonne découverte,

Christian Buil


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Sol'Ex (for Solar Explorer) is a small instrument that you can make in 3D printing and with a minimum of means. It allows you to observe the solar atmosphere in the Hydrogen line, but also any other line of your choice. Of course here, it is question of a spectrograph, more precisely, a spectroheliograph.

First, a web site exists, which details the reasons for the project, how to make the instrument and how to use it. See here :

http://www.astrosurf.com/solex/

(In French langage for the moment, but many illustrations are present and easy to translate).

Of course, to get to the end of this achievement you must by one means or another, you can make small parts in 3D printing, either because you have a printer, or, through friends, members of a club, your company, a local FabLab, etc. You can download all the necessary files from the Solex site. Today there is no other way, because there is no mechanical parts kit.

On the other hand, a kit of the necessary optical parts exists, which will considerably facilitate your task if you want to get started. This kit includes a high performance 10 micron slit, a set of two lenses that I calculated especially for the Sol'Ex project and made specifically (I included special glasses in the formula for maximum performance), a 2400 lines/mm diffraction grating.

It will cost you a little less than 400 euros including tax (excluding shipping costs). You will find a link to a product sheet from Shelyak Instruments company on the Solex website. You benefit from this preferential rate until February 28, 2021 as part of a subscription.

I am aware that this may represent a fairly high sum for equipment to build yourself (know that the maximum has been done to lower the cost as much as possible), but I hope that reading the site will show you that the said sum will be quickly paid for itself (incidentally, we can consider doing much more than solar imaging, you will see, stellar spectrography for example).

Christian buil

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Robin Leadbeater
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Re: Démarrage du projet Sol'Ex

Post by Robin Leadbeater »

Hello Christian,

I see you damaged a glass slit using it with direct sunlight through a telescope so use a Herschel wedge.
http://www.astrosurf.com/solex/observation.html
I assume this warning also applies to the modern LHIRES III with the glass slit? For example here
http://www.threehillsobservatory.co.uk/ ... tra_29.htm
where I used a 45mm f9 telescope with the original metal slit without a filter. If so I will add a warning to the page

Thanks
Robin

(Also posted on spectro_l)
Last edited by Robin Leadbeater on Fri Jan 22, 2021 2:50 pm, edited 1 time in total.
LHIRES III #29 ATIK314 ALPY 600/200 ATIK428 Star Analyser 100/200 C11 EQ6
http://www.threehillsobservatory.co.uk
Robin Leadbeater
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Re: Démarrage du projet Sol'Ex

Post by Robin Leadbeater »

Would it be possible to use the same lens design to improve the performance of the doublet in the LHIRES III ? (I would be happy to pay for a better lens to improve the loss of resolution in the violet due to chromatism in low resolution spectra and around the Ca HK lines seen even at high resolution)

Thanks
Robin
LHIRES III #29 ATIK314 ALPY 600/200 ATIK428 Star Analyser 100/200 C11 EQ6
http://www.threehillsobservatory.co.uk
Olivier GARDE
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Re: Démarrage du projet Sol'Ex

Post by Olivier GARDE »

Robin Leadbeater wrote:Would it be possible to use the same lens design to improve the performance of the doublet in the LHIRES III ? (I would be happy to pay for a better lens to improve the loss of resolution in the violet due to chromatism in low resolution spectra and around the Ca HK lines seen even at high resolution)
I don' know Robin ... The Sol'Ex lens have a focal length of 60mm and 80mm, I'm not sure that the LHIRES II have the same doublet focal length.
Last edited by Olivier GARDE on Mon Jan 25, 2021 4:28 pm, edited 2 times in total.
LHIRES III #5, LISA, e-Shel, C14, RC400 Astrosib, AP1600
http://o.garde.free.fr/astro/Spectro1/Bienvenue.html
Olivier GARDE
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Re: Démarrage du projet Sol'Ex

Post by Olivier GARDE »

a quick message to tell you that we have already reached the minimum order for the Sol'Ex optical kit.

The price indicated on the Shelyak website remains valid until February 28, when the kit subscription ends.

The price will probably not be the same afterwards.

To order the optical Sol'Ex kit :
https://www.shelyak.com/produit/es0023- ... t/?lang=en
LHIRES III #5, LISA, e-Shel, C14, RC400 Astrosib, AP1600
http://o.garde.free.fr/astro/Spectro1/Bienvenue.html
Robin Leadbeater
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Re: Démarrage du projet Sol'Ex

Post by Robin Leadbeater »

Olivier GARDE wrote:
Robin Leadbeater wrote:Would it be possible to use the same lens design to improve the performance of the doublet in the LHIRES III ? (I would be happy to pay for a better lens to improve the loss of resolution in the violet due to chromatism in low resolution spectra and around the Ca HK lines seen even at high resolution)
I don' know Robin ... The Sol'Ex lens have a focal length of 60mm and 80mm, I'm not sure that the LHIRES II have the same doublet focal length.
Hi Olivier,

I know these specific lenses will not fit the LHIRES but Christian has designed these lenses to have lower chromatism so I was wondering if he could use the same design for a lens specially for the LHIRES III. The chromatism of the standard doublet is a known weak point of the LHIRES design and I think many LHIRES users would be interested if a better lens was available.

Cheers
Robin
LHIRES III #29 ATIK314 ALPY 600/200 ATIK428 Star Analyser 100/200 C11 EQ6
http://www.threehillsobservatory.co.uk
Olivier GARDE
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Re: Démarrage du projet Sol'Ex

Post by Olivier GARDE »

English version below

Hier, nous avons eu l'atelier en ligne sur le Sol'Ex initié par Christian Buil.
Vous pouvez voir ou revoir cet atelier ici :
https://www.youtube.com/watch?v=ORTBOOXAHOk&t=1005s

Si vous souhaitez souscrire au kit optique du Sol'Ex, merci de consulter ce lien :
https://www.shelyak.com/produit/es0023- ... que-solex/


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Yesterday, we had a workshop on the Sol'Ex project initiated by Christian Buil.

You can watch it in replay here :
https://www.youtube.com/watch?v=ORTBOOXAHOk&t=1005s

If you want to subscribe the Sol'Ex optical kit, please go to this link :
https://www.shelyak.com/produit/es0023- ... t/?lang=en

The subscription end the 28 february 2021 with this special price.
LHIRES III #5, LISA, e-Shel, C14, RC400 Astrosib, AP1600
http://o.garde.free.fr/astro/Spectro1/Bienvenue.html
Olivier GARDE
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Re: Démarrage du projet Sol'Ex

Post by Olivier GARDE »

Je viens de créer une liste dédiée aux échanges sur le projet Sol’Ex :
https://groups.io/g/Solex-project

I have just created a discussion list dedicated to the Sol’Ex project :
https://groups.io/g/Solex-project
LHIRES III #5, LISA, e-Shel, C14, RC400 Astrosib, AP1600
http://o.garde.free.fr/astro/Spectro1/Bienvenue.html
Francois Cochard
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Re: Démarrage du projet Sol'Ex

Post by Francois Cochard »

Hi,
A quick reply to Robin about the posibility to reuse the Sol'Ex doublets in the Lhires III.
The quick answer is NO, because the Lhires III uses the same lens for collimator and objective (Littrow architecture), where the UVEX has two different lens.
But anyway, I would be curious to see how both doublets could behave in the Lhires III... we never know (:>)
Friendly,
François
Robin Leadbeater
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Re: Démarrage du projet Sol'Ex

Post by Robin Leadbeater »

Francois Cochard wrote:Hi,
A quick reply to Robin about the posibility to reuse the Sol'Ex doublets in the Lhires III.
The quick answer is NO, because the Lhires III uses the same lens for collimator and objective (Littrow architecture), where the UVEX has two different lens.
But anyway, I would be curious to see how both doublets could behave in the Lhires III... we never know (:>)
Friendly,
François
Hi Francois,

I meant a lens specially designed for the LHIRES instead of the "off the shelf" doublet. Perhaps one with more elements combining the effects of the Sol'Ex lenses? (What would be the cost of an apochromatic triplet for example?)
(I have even tried experimenting tilting the camera to improve the loss of focus in the violet but the change in focus with wavelength of the simple doublet is too much)

The ALPY, and now the Sol'Ex have specially designed lenses with lower chromatism. The LHIRES (and LISA) have poorer performance at the blue end by comparison and would benefit from more optimised lenses if it were possible

Cheers
Robin
LHIRES III #29 ATIK314 ALPY 600/200 ATIK428 Star Analyser 100/200 C11 EQ6
http://www.threehillsobservatory.co.uk
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