Cloudyifr When I put a FITs file into Siril it's only B&W and there are not three separate RGB channels as when I use the NEF file off of the card in the camera.
Curtis,
Check on Google for "Color Filter Array" (CFA) or "Bayer Filter." The Wikipedia page for "Color Filter Array" has a good explanation for casual readers.
Just like with DSLR, all color cameras that uses a CMOS sensor are monochrome cameras with a CFA layer. (The only exception is the Foveon sensor -- I still have my old Sigma camera that uses a Foveon sensor).
When you download an image from such a sensor in raw form (for example, in FITS format), they are simply an array of gray scaled values ("monochrome").
Some of the pixels represent a red pixel, some represent green and some represent blue.
Post processing then combines all these grayscale values to produce a lower resolution color image, using a process usually called deBayering. The quality (how minimal are the artifacts) will depend on how good the post processor is -- that is why you always want to start with a raw grayscaled image.
To deBayer, the post processor needs to know that the image came from a "color" camera, and it needs to know the pattern of the colors.
You just need to tell Siril to debayer your raw image with the appropriate Bayer pattern for your particular camera.
Chen
