Started by G. Hatfield , Mar 26 2015 01:54 PM Posted 26 March 2015 – 01:54 PM
Forgive me if you already know about this feature of PixInsight, but I was unaware of it. These two scripts can plate solve and label your images.
ImageSolver (under image analysis)
Annotateimage (under render)
And there is even some directions to go with the plate solver. You must give an approximate RA and DEC (it can’t do it blind) and when it is done, it writes the info to the image file. Then use the annotater to label the image. Pretty amazing. See the attached examples. In the following post, I show an example of the labeled image.
Edited by G. Hatfield, 26 March 2015 – 02:01 PM.
PixInsight Testversion für 45 Tage besorgt
Aus dem Kamera-Dropdown haben wir nun “File Open dialog” ausgewählt. Der Setup-Button hat dann keine Funktion, aber wenn man jetzt auf den Button “Capture and Solve” drückt, kann man ein bereits vorhandenes Astrofoto auswaäheln, was dann “gesolved” wird……
Nach Ablauf der 45 Tage kommt dann leider dieses Bild:
Abbildung 1: Software PixInsight nach 45 Tagen (Google Drive: PixInsight45.jpg)
PixInsight Authentification Error (45 day Trial period)
First, I was having trouble getting the plate solve script to work on some of my images. I would put in the focal length of my scope and the pixel size of the camera, but it would “blow up” and not solve the image. Then it occurred to me that the images I was using had been reduced in size. When I put in a corrected image scale (i.e., corrected for the fact that I had reduced the image size by 2/3, from 5094 x 3414 pixels to 1728 x 1158 pixels) it worked on every image. So my “native” image scale, which is about 1.38 arcsec/pixel, had to be entered as 4 arcsec/pixel for the resized (not cropped) image.
Also the search function works very well. I was looking up the RA and DEC in SkyX, but the search function will find these values for most objects even when the common name is used.
Sometimes the labeling from the Tycho-2 catalog can overwhelm the image. If you highlight this catalog a filter can be applied to limit the stars to a particular mag range.
George
Edited by G. Hatfield, 28 March 2015 – 03:19 PM.
I’ve learned a couple of things.
First, I was having trouble getting the plate solve script to work on some of my images. I would put in the focal length of my scope and the pixel size of the camera, but it would “blow up” and not solve the image. Then it occurred to me that the images I was using had been reduced in size. When I put in a corrected image scale (i.e., corrected for the fact that I had reduced the image size by 2/3, from 5094 x 3414 pixels to 1728 x 1158 pixels) it worked on every image. So my “native” image scale, which is about 1.38 arcsec/pixel, had to be entered as 4 arcsec/pixel for the resized (not cropped) image.
Also the search function works very well. I was looking up the RA and DEC in SkyX, but the search function will find these values for most objects even when the common name is used.
Sometimes the labeling from the Tycho-2 catalog can overwhelm the image. If you highlight this catalog a filter can be applied to limit the stars to a particular mag range.
George
Today, while working on the Orion Nebula, I also realized the same issue of pixel size for an image that was cropped/enlarged. It’s pretty finicky with the tolerance of the input! I suppose it forces better cataloging of image attributes. Like they say, garbage in garbage out!
I recently learned another critical factor in setting this up. The limit magnitude must be set to about 18 for it to work in some instances. In fact, if you do that and set the RA and DEC correctly it will often work with everything else with defaults.
George
So Astrometry.net knows how to plate solve **without** RA/DEC and FOV/Scale hints (Blind Solver). So why does PI require these hints and not blind solve also?
You have the bizarre situation if you pick up an old image that you have forgotten where it was in the sky and want to annotate it you have send if off to Astrometry.net for analysis to be able to tell PI where it actually is and at what scale?
I think the Astrobin guys did an excellent job piggy-backing on Astrometry.net web services to support their annotation tool. I wonder if you can call up Astrometry.net via PI in a similar manner to seed the location/scale info into the PI annotator?? Anyone know?
So Astrometry.net knows how to plate solve **without** RA/DEC and FOV/Scale hints (Blind Solver). So why does PI require these hints and not blind solve also?
You have the bizarre situation if you pick up an old image that you have forgotten where it was in the sky and want to annotate it you have send if off to Astrometry.net for analysis to be able to tell PI where it actually is and at what scale?
I think the Astrobin guys did an excellent job piggy-backing on Astrometry.net web services to support their annotation tool. I wonder if you can call up Astrometry.net via PI in a similar manner to seed the location/scale info into the PI annotator?? Anyone know?
You can upoad an image to Astrometry.net and then download the plate solved .fts file that has the headers embedded. Feed that to PI Annotate script.
