I keep coming across the same pattern in black splotches (sometimes white) on various sets. What is this? (play through usually goes right, left, up, down (or some variation). Also, missed an asteroid in here because of static 😦 Still can't see it. Thoughts?
The movement pattern is usually up, down & right and left, a common movement pattern for artifacts.
The black splotches are known as flat field defects. From wiki:
Flat-field correction is a technique used to improve quality in digital imaging. The goal is to remove artifacts from 2-D images that are caused by variations in the pixel-to-pixel sensitivity of the detector and/or by distortions in the optical path. It is a standard calibration procedure in everything from pocket digital cameras to giant telescopes.
Defects in this flat field cause too much to be subtracted from the image in spots like this, creating these flat field defect artifacts that you see.