Bad efficiency of the eShel from shelyak

Design, construction, tuning of spectroscopes
Information and discussion about softwares (telescope remote, autoguiding, acquisition, spectral processing ...)

Re: Bad efficiency of the eShel from shelyak

Postby Berthold Stober » Sun Nov 10, 2019 2:53 pm

see artefacts from ISIS.png
There was used the same files for both reductions . left = ISIS right = midas
Thank you for your answer but please look the adnex. It seems quite obviously that ISIS produces those "fringes" and it destroy so my spectra. It' rather clear that it is not caused by hardware problems.
I am not at all happy about this, I would prefer to go on with ISIS since Midas is not so easy to use.........but at the moment I have no choice!
Berthold Stober
 
Posts: 26
Joined: Thu Apr 21, 2016 8:15 pm

Re: Bad efficiency of the eShel from shelyak

Postby Olivier GARDE » Sun Nov 10, 2019 3:56 pm

Hi Berthold,

In the screenshot of the ISIS main page, you checked:
- Sum before
- Median Filter
- Function de blaze lissé

When I process my eshel spectra (with an ATIK 460ex CCD), I check only :
- Optimal Binning
- Cosmic Rays filters

Do you use a CMOS camera ?

Christian wrote a page that explains the checkboxes
http://www.astrosurf.com/buil/isis/eshe ... index.html
LHIRES III #5, LISA, e-Shel, C14, RC400 Astrosib, AP1600
http://o.garde.free.fr/astro/Spectro1/Bienvenue.html
Olivier GARDE
 
Posts: 979
Joined: Thu Sep 29, 2011 6:35 am
Location: Rhône Alpes FRANCE

Re: Bad efficiency of the eShel from shelyak

Postby Berthold Stober » Sun Nov 10, 2019 4:56 pm

see artefacts from ISIS.png
The same files reduced with ISIS (left!) and midas (right)
Berthold Stober
 
Posts: 26
Joined: Thu Apr 21, 2016 8:15 pm

Re: Bad efficiency of the eShel from shelyak

Postby James Foster » Mon Nov 11, 2019 12:21 am

To: Berthold,

Christian gave a lot of great advice.....I don't have an eShel myself (as mentioned earlier) but I notice you have a Kaf3200 sensor which may not be optimal for
the eShel. I used this same sensor for my old L-200, and I got a ripple effect; abiet without using flats which were not part of that device, unlike Alpy600, LISA,
or LhiresIII. Since I acquired the Atik line of cameras for my Shelyak line of spectroscopes, this problem has gone away; sold my old L-200 last year.

Christian wrote this article on thew advantages using the Atik460ex with eShel: http://www.astrosurf.com/buil/eshel4/eval_en.htm

James
James Foster
Lhires III (2400/1800/600 ln/mm Grat) Spectroscope,
LISA IR/Visual Spectroscope (IR Configured Presently)
Alpy 600 with Guide/Calibration modules and Photometric slit
Star Analyzer 200
James Foster
 
Posts: 326
Joined: Sun Jan 24, 2016 7:14 am

Re: Bad efficiency of the eShel from shelyak

Postby Christian Buil » Mon Nov 11, 2019 2:32 am

Hi Berthold,

Unselect the option "Median filter" and compare. The problem is here, I suspect.

The median filtering option is only for very well sampled spectral (typically eShel spectra taken by using small pixels CMOS camera).

Christian
Christian Buil
 
Posts: 1289
Joined: Mon Sep 26, 2011 6:59 pm

Re: Bad efficiency of the eShel from shelyak

Postby Berthold Stober » Mon Nov 11, 2019 5:48 pm

Denem191107_Na_midas.png
no "waves" are to be seen in the continuum!
Deneb191107_Na_ISIS.png
Artefacts caused by ISIS


The problem is obviously even I used "optimal binning" in ISIIS.

berthold
Berthold Stober
 
Posts: 26
Joined: Thu Apr 21, 2016 8:15 pm

Re: Bad efficiency of the eShel from shelyak

Postby etienne bertrand » Mon Nov 11, 2019 8:48 pm

Possible "cosmic rays filter" if the spectr is very short ?
etienne bertrand
 
Posts: 844
Joined: Mon Aug 31, 2015 11:26 am

Re: Bad efficiency of the eShel from shelyak

Postby Berthold Stober » Tue Nov 12, 2019 9:52 am

Hello,

I have had an ATIK 460ex to avoid those ripples. No effect. The same probleme was to see as demonstrated with the 460ex! That is not caused by the detector! Please see the results with MIDAS!

berthold
Berthold Stober
 
Posts: 26
Joined: Thu Apr 21, 2016 8:15 pm

Re: Bad efficiency of the eShel from shelyak

Postby Berthold Stober » Tue Nov 12, 2019 2:58 pm

Deneb191107 with ISIS.png
Deneb191107 with ISIS.png
Deneb191107 with ISIS.png


No, it is the same with ISIS
there must be a problem with ISIS
unfortunately I can't send *.xml
that's not a probleme of the hardware.

berthold
Berthold Stober
 
Posts: 26
Joined: Thu Apr 21, 2016 8:15 pm

Previous

Return to Spectroscopes and Softwares

Who is online

Users browsing this forum: Google [Bot] and 2 guests

x