This is an image of IC1396 in which I wanted to show more of the nebula than just the Elephant Trunk. It is the result of over 3 hours of 20 second images in EQ mode and mosaic. Note the “mosaic-like” overlay toward the middle of the image. Is this a bug? Is there something I need to do to eliminate this? Note: this is straight out of SeeStar stack with some tweaking of contrast and exposure.
This is because during the mosaic capture, the light pollution in the environment caused noticeable stitching artifacts. You can first retake flat frames, and then use Siril to perform DBE (Background Extraction) in post-processing to correct it.
