spectro-aras.com

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!

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

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

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

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

berthold

Possible "cosmic rays filter" if the spectr is very short ?

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

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

Hi,

I overlooked the message of Christian, I don’t know why. Please excuse me.

Martin Dubs pointed this out to me once more, not to use the “median filtering” .What I don’t understand: I used at time CMOS detectors, but it was the same.

Berthold