Photometric Color Calibration

dave summa

I love this tool.  It was flawless in use, and the corrections had such an impact.  Lately, it NEVER works.  I have been digging.  

The FITS header info for focal length is some random number.  I edit that back to the correct value.  I noticed that the RA and Dec are likewise off.  Example M45 is supposed to be at 03 47 RA and 24:07 dec.  However, the FITS header says 04 04 and 26:17.  When I manually put the correct info for FL, RA and dec into the PCC, it always fails.  When I edit the FITS headers (just in case PCC queries the FITS header during execution after starting with the input data fields from PCC) it still fails.  I looked at the date/time and both appear correct.  

What's going on?  I really want my PCC back.  Especially to color correct for M45 in my full moon Bortle 7 photo...

Log 

Reading image:

C:/Users/daves/AppData/Local/Temp/PCC_T_8TGB5L5BU7GH.xisf

Loading image: w=5451 h=4866 n=3 RGB UInt16

14 image properties

19 FITS keyword(s) extracted.

* Using an automatically calculated limit magnitude of 12.42.

* Using the automatically selected GaiaDR2 catalog.

Seed parameters for plate solving:

Center coordinates: RA = 00 15 08.000, Dec = +24 07 00.00

Resolution: 1.570 as/px

Starting StarAlignment iteration

* Target image: Limiting to 500 brightest stars.

Matching stars: done

109 putative star pair matches.

BlockHead

Hi Dave.

First I note you are using GAIADR2... but I think DR3 is the latest/greatest.

DR2 might have some holes in some parts of the sky.....

This may or may not be it....but just so we can be on the same page...

any chance you are up for getting DR3?

-the Blockhead

John HULME

Hi,

I am new to Pixinsight and astrophotography so bear that in mind but:

PCC has been causing me to tear out what is left of my hair. I have been processing an image of M42 with L, R, G and B taken with an ASI1600 MM Pro and ASIAir. My integrations have what seem to be randomly generated (but consistent) RA and Dec. No matter what I enter in PCC these values are overriden.

I edited the header with Fits Header by changing the values (first try) and removing the values (second try). I confirmed that the edits were implemented. I saved the files, closed them and reopened them. My edits were in place but when I tried PCC the old values were still there. I closed PI, reset PCC - always the same result. There must be hidden metadata which PCC extracts, not the visible Fits header.

I have found a workaround: By using the ImageSolver script I seem to be able to embed correct values which then allows PCC to perform its miracle.

There must be a better way?

BlockHead

Yes, you have multiple entries in your Fits Header for the coordinates. 

Your acquisition software is writing, presumably, bad coordinates into the header file. 

In the meantime, check "ignore existing metadata" under the Plate Solving options of PCC.

-the Blockhead