Problem with debayer Canon EOS images

[konstantinos75]

Hi

I use TheSkyx Pro to connect my Canon EOS 450D camera. The data acquisition mode I have chosen is "Raw Bayer Data".

I have told TheSkyx to save the images as FIT format.

This is the information provided by TheSkyx about this mode

1. Raw Bayer Data - Only images shot in this mode can be converted to color later. This mode returns the raw Bayer matrix data from the camera. Raw Bayer data contains four pixels cells that contain one red, one blue, and two green pixels (laid out in RGGB order). The image returned to TheSkyX is in the native resolution of the camera. Image link works quite well on this data despite that it appears to be missing pixels (the blue pixels tend to be very dark). When magnified you will see a characteristic screen door type pattern. This data does not show in color. A post processing program is required (PixInsight, Nebulosity, etc.) to convert the Bayer data to a color image. Best results are obtained by doing image calibration (darks and flats) on this raw pattern before conversion to color. You must also convert to color BEFORE image alignment and stacking operations, or the color data will be lost.

 

Now you can bin 2x2 while in Raw Bayer mode, which is effectively a summed luminance mode (you CANNOT recover color data if you bin)

Then I pass a FIT image to Pixinsight. I make image calibration then I proceed to debayer the image so that color will be shown.

The problem I get is that on the star halos I see some pink/red ringing side effects.

I have tried all debayering combinations in Pixinsight and the problem is always there.

Does anybody has experienced this problem and has some solution to it other than process further this image e.g. in Photoshop play with selective colors to get rid of the artifacts?

Thank you

[pyrasanth]

Try a trial copy of Ccdstack2 & use the debayer feature in that program. If you get the same artifact then the issue is the data. If not then it's something in PixInsight. Only trial & error can determine where you should be looking to resolve the issue.

[konstantinos75]

Hi

This time I have told TheSkyx to save the images as RAW format also.

When I load the RAW image in Pixinsight and debayer it afterwards, the problem no longer appears.

So there's must be an issue with TheSkyx saving Canon EOS 450d images as FIT format.

I cannot explain this otherway...