PhotometricColorCalibration (PixInsight 1.8.9-2) is different from NGC1333 Workflow videos

Richard Lewis

Hi Adam,

I'm following along and at the color calibration stage, I noticed with screen is quite different. Especially with regard to Background Neutralization since the limits are now in terms of standard deviation. I also see that even though I have GAIA installed, it's trying to use the online APASS catalog and there doesn't seem to be a way to select GAIA. 

I've selected an ROI with a preview but when I run I get the following (see below). What would you recommend I set?

I gave SpectroPhotometricCalibration a try instead and seems to work and produce similar results to your example. 

* Using the APASS DR9 (VizieR) catalog (automatically selected).

** Warning: Not using a local XPSD database - online catalog access can lead to suboptimal calibration results.

Limit magnitude: 11.24

* Searching catalog sources

https://vizier.cds.unistra.fr/viz-bin/asu-tsv?-source=II/336/apass9&-c=52.371593 30.735921&-c.r=2.911821&-c.u=deg&-out.form=|&-out.max=50000&-out.add=_RAJ,_DEJ&-out=Bmag&-out=Vmag&-out=r'mag&Vmag=<11.24

19958 bytes transferred (unknown size)

236 catalog sources found.

Saturation threshold: 0.7107

* Extracting PSF signal samples

Fitting 10734 stars: done

Fitting 9985 stars: done

Fitting 9044 stars: done

* Computing color calibration functions

Robust linear regression (R-G):   0%

*** Error: Insufficient data: only 0 sample(s) are available; at least 5 are required.

Reading swap files...

BlockHead

Hi Richard,

A couple of notes. Always look at the published dates for content. In some cases you need to adjust since Pixinsight has changed since I made the video.

In the same breath, consider that I update my content as quickly as I can. I did update the instructional content for SPCC and show how to set it up (using GAIA) as well as updating workflow videos. I even have a specific video on the BN neutralization mechanism and how it works.  Just a few weeks ago I created and released the LATEST workflow video of NGC 1491. It is at the top of the WORKFLOW list of videos. So if you watch NGC 1491 everything is current. Then you can apply that knowledge to NGC 1333 (where things are out-of-date).

You did remind me, however, that I need to update my Fundamentals path to include NGC 1491 now instead of NGC 1333 being most current.

-the Blockhead

BlockHead

By the way, my latest workflow also addresses the "insufficient samples" error you got. I explain what is happening and what to do.

I hope you will agree after you watch my content, I have you covered.

-the Blockhead

James Henke

I just wanted to add - kudos on the NGC 1491 processing workflow!

Very well done - very informative, instructional with the latest tools and covered the workflow in a detailed, yet concise manner at a good pace. 

Thank you for putting this in Fundamentals and will definitely be an excellent and useful resource!

NGC 1491 WORKFLOW

NGC 1491 WORKFLOW