I didn’t intentionally dither the subframes. I don’t think the Star Adventurer
has that capability. Could be the shutter going cathunk between frames caused
the Star Adventurer to skip a bit? But yeah, what you suggest would cause the
hot pixels to move relative to the stars.
On Oct 13, 2018, at 12:13 PM, Paul Lind <pulind@xxxxx> wrote:
I had to copy the image and blow it up to see the trails. By the way, the
hot pixels actually do stay at the same location, but if the position of the
stars is dithered between frames (that is, the camera is dithered) then
stacking the subs will line up the stars and cause the hot pixels to move.
It looks like your camera dithered in a more or less straight line.
It's interesting that each trail consists of one color of dots? I have seen
this effect before, but .I'd get multi-color dots in each trail because I
dithered my monochrome camera between each color filter exposure. Now I
always attack the hot pixels themselves using Cosmetic Correction during
pre-processing. Sigma clipping is still used in stacking, but mostly to
eliminate satellite trails.