spectro-aras.com

Rainer, I do not think the answer is as straight as I mentionned above. First, you do not want to go faster than F/5 so it is better to be at F/6 rather than F/4 for exemple. Now, how do you compare F/5 and F/8... F/8 will end up with a lower beam within the LISA so you will shine less grooves on th...

Rainer,

it would depend on seeing but with a 8", I would personally leave it at F/8 with a 23µm slit and save the light loss within the focal reducer.

Cordialement,
Olivier Thizy
Vous ne verrez plus des étoiles comme avant !
http://www.shelyak.com/en/

Rainer, You do not "have to" buy a new slit. The 23µm and 35µm work in most cases. Look at results beeing published with those standard slits... We made an optional slit available with 50-75-100µm slits and a 19µm hole. The large slits are mainly intended to large telescope (>24inch typica...

Rainer, The input collimator is F/5. If you use a faster scope, you will loose light inside the spectrograph as light will go outside the collimator diameter. But you can always use a slower scope such as F/6.3 or even F/10 scope. The disadvantage of doing so is that you will loose more light at the...

Check out also an animation of a mira spectrum versus light curve:
http://newb6.u-strasbg.fr/~lancon/anims.html

Cordialement,
Olivier Thizy
Vous ne verrez plus des étoiles comme avant !
http://www.shelyak.com/en/

Hello, Mira are variable stars with a long period (several months) and very large amplitude. A list of maxima is available for several mira stars: http://etoilesvariables.fr/public/previsionsMira/prev2011.pdf They are excellent targets for low resolution work with Star Analyser, Lhires III (150 gr/m...

Quelques photos supplémentaires...
Cordialement,
Olivier

Bonjour, en quasi direct live du WETAL, voici quelques photos du début de cette rencontre avec une centaine d'inscrits en ce week-end du 11-11-11 ! web_IMG_3851 Salle.jpg web_IMG_3848 Pierre.jpg web_IMG_3845 Accueil.jpg Les prochaines photos seront sur la gallerie officielle du CALA: http://photos.c...

9h combined exposure... I believe this is the longuest I have ever seen!!!

Anyway, result is really nice!

Cordialement,
Olivier Thizy
Vous ne verrez plus des étoiles comme avant !
http://www.shelyak.com/en/

Stéphane, le "flat" qui est fait avec les LEDs ne sert qu'à la géométrie du spectrographe. Le temps de pose et l'évolution temporelle associée n'est donc pas importante. Elle l'est plus pour le "Tungsten" mais cette lampe est moins sensible à ce phénomène. C'est aussi une des rai...