I recently took some pictures of Andromeda with a SA-GTI and a lumix g85 with the lumix 100-300mm, but the noise of the final image is really bad. Here is the first picture taken with a total of 2.5 hours (315*30s):

With this noise, I thought it was waking noise due to the almost perfect polar alignment. Since I don’t have a dedicated computer and autoguider to dither, I just did it manually by moving the axis of the mount a bit to move the object on the sensor every half hour. For reference, the object stayed within the center cell of the grid of thirds, so I’d say I moved it a few hundred pixels every time in different directions. Here is the result (293*30s):

(Both pictures are processed in siril with green noise removed at the end) The noise stripes are smaller, but there is still a lot of noise in my opinion. It this due to the sort total exposure, or might it be walking noise? How can I reduce the noise without buying new equipment?