I calibrated my frames in CCDStack, then wish to save them for use with RegiStar (and then continue on with CCDStack). I chose 16-bit FITS (unsigned) for this (I use an ST-2000XM camera). In RegiStar when opening a frame, if I choose the unsigned option in the Open dialog, the brighter stars have "black holes" in their centers. If I do not specify unsigned, the image looks "normal" but I'm worried about this apparent signed/unsigned flip flopping.

Not sure if RegiStar (1.0.7) can "handle" 32-bit floating point, or I'd use that. It seemed to open them OK, but again, I'm wondering what's going on behind the scenes.

Suggestions?

Regards,
Lou Marchesi

Do the stars look OK if you re-open them in CCDStack?

Try sending 16 bit TIFF to Registar.

Stan

I have been saving my images as 32 bit FITS and Registar seems to open them ok. When I am done the I open them in CCD Stack and continue the process. The only draw back is I have to use 2 programs which is why I have been using CCD IS lately. But I tried saving the way you did and did not have the problem you are seeing.

I have been using CCD IS mostly these days but sometimes it fails and I either use the normal select star align in CCD Stack or Registar which always works.

Dean