Focus a spectrum

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cardanoc
Posts: 3
Joined: 13 Feb 2019, 16:33

Focus a spectrum

Post by cardanoc » 18 Jun 2020, 19:01

Hi,
In SP4, I see that there are features for focusing a spectrum. I assume that it is similar to focusing on a star.

1. Take a full image with the main camera. (i.e., click the “Start” button and record a spectral line.)
2. Select a rectangle around an absorption line(instead of a star)
3. Click the “Focus” button on the “Focus/Guide” tabfolder on the “Camera” window.
4. On the “Focus” window, select the “Spectrum reference line” on dropdown in the lower right hand corner.

At this point, I’m not sure how to interpret the numbers on the “Focus” window.

Thank You!

Conrad Cardano
Dye Hill Observatory
Rhode Island, USA

fabdev
Posts: 191
Joined: 03 Dec 2018, 21:43

Re: Focus a spectrum

Post by fabdev » 18 Jun 2020, 20:32

Hi,
yes, that procedure is exact.
The function is intended for reference lamps which give bright emission lines. The emission line must be vertical. The numbers are not significative, simply the higher the better.
It was suggested some time ago by Ken from: http://astronomicalspectroscopy.com/
Clear skies,
Fabio.

merlin66
Posts: 10
Joined: 08 Jan 2019, 05:38

Re: Focus a spectrum

Post by merlin66 » 19 Jun 2020, 06:27

Conrad,
A Fabio mentioned, this feature was to assist in the focus of reference lamp emission lines with the slit spectrograph.
This is a critical step in ensuring critical spectral image focusing and resolution.

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