If I look at an image taken using MaxIm though APCC APPM (AP app) the FITS header gives a image scale and focal length that is incorrect according to Astrometry. The true focal length of this 24" f/7 scope is 4200 mm but the FITS header of the raw image taken with MaxIm shows 3038 mm. Of course this fails to solve or I'm guessing this is causing it to fail although the same images run in Astrometry all solve. And the FITS header then has the correct focal length. I've checked the settings in Maxim and they appear correct so I'm completely stumped on what is causing the issue. It doesn't help that it's 3-4 am here while the scope operates on the opposite coast. Any hints as to what might be causing these issues? Scope ASA600 24" f/7 RC Mount AP3600GTO Camera AC4040BSI Acquisition Imaging Software MaxIm DL version 6.50 Mapping Software APCC/APPM by Astro Physics Hope I've covered it well....
OK getting weirder by the moment, the same image opened in MaxIm report s a 3038 focal length and the same in Pix Insight shows 4235. The design is for 4200 mm but which one is correct?
That's totally inaccurate. The difference is the raw MaxIm FITS file versus the FITS header after Astrometry plate solve. But the incorrect reading of focal length in the raw file is keeping any mapping from progressing. I also see differences in image scale almost always with different X/Y scales for a 9 micron chip in a 4096 x4096 array. This was taken with the 6.50 update. Tempted to roll back to 6.40 and see if any difference.....
If it is any help... What is currently configured under MaxIm > File menu > Settings > Site and Optics for Main Telescope, > Focal Length? Unless you solve the image in MaxIm with Pinpoint to get a true pixel scale and focal length then the info in MaxIm's FITs header is just a prediction based on pixel size, binning and the focal length that you entered in the Site and Optics tab. The true focal length of the optical tube may be quite different to what the telescope manufacturer quotes and I would normally plate solve a few images in PinPoint (or Astrometry) to get the true focal length and then enter that figure in MaxIm's Site and Optics tab so that when unsolved MaxIm FITs are exported to PixInsight then it should be happy when it recalculates a plate solve solution based on the true focal length and pixel scale that is in the FITs header. William.
