Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Astrobin can plate solve my image but not PI - hints?

  • Please log in to reply
3 replies to this topic

#1 Tom K

Tom K

    Messenger

  • *****
  • topic starter
  • Posts: 401
  • Joined: 19 Jan 2010
  • Loc: Escondido, CA

Posted 12 January 2019 - 12:33 PM

Greetings

 

I have an image of the Rosette nebula that astrobin was able to platesolve without problems, but PI won't for some reason.   I am not getting enough star pair matches.  Clearly I am doing something wrong here.  Have any of you experienced this with the plate solve system in PI?   I was hoping to apply some photmetric color calibration to my image.

 

One thing I did notice is that when I acquire the focal length and pixel size from the image they appear to be incorrect.   I am imaging at 510mm (Orion 80ED with 0.85 FR) and use a Canon 500D which has a pixel size of 4.7 microns from my understanding.   PI reports the focal length at 996 mm and a pixel size of 9.  I have tried it with PI's values and values I enter directly with the same result.

 

I have used the tool in PI to set the coordinates on NGC2244 and those look correct.

 

I am sure that I must be missing something simple here - any hints?

 

Thanks

 

Tom


Edited by Tom K, 12 January 2019 - 12:34 PM.


#2 fmeschia

fmeschia

    Viking 1

  • *****
  • Posts: 960
  • Joined: 20 May 2016
  • Loc: Mountain View, CA

Posted 12 January 2019 - 02:18 PM

Plate solving works best (and Photometric Color Calibration works *only*) on linear images. Are you running it while the image is still in its linear stage?

 

For plate solving, what’s important is the image scale in arcsecs per pixel. 510 mm on 4.7 µm pixels is the image scale as 996 mm on 9 µm pixels. If you provide either pair as a starting point to PI, it should give the same result.

 

Francesco



#3 Tom K

Tom K

    Messenger

  • *****
  • topic starter
  • Posts: 401
  • Joined: 19 Jan 2010
  • Loc: Escondido, CA

Posted 12 January 2019 - 03:21 PM

Francesco - thanks for the tip - I had already stretched the image so that must be the issue.

 

I will make sure to perform this process while linear in the future!

 

Thanks

 

Tom



#4 RareBird

RareBird

    Sputnik

  • -----
  • Posts: 36
  • Joined: 11 Feb 2015

Posted 12 January 2019 - 09:19 PM

One stumbling block I had was PI not liking any previews in the image to be solved. 

 

Arlo


  • fmeschia likes this


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics