Squiggles...

[Peter Reader]

Hi all,

I'm getting squiggly artefacts in my image of Andromeda...

I think these are artefacts caused by dust on my camera chip. How do I get rid of these? I have tried wiping the chip but the dust particles are not removed... they show up as blue and red pixels... which is odd isn't it?

Please help!

Thanks!

[Smeg]

Squiggly Andromadean aliens?

Has your camera got an Ultrasonic dust cleaning mode? Try that.. but that's just for the mirror isn't it?

or Manual clean mode and that flips up the mirror and get a Hairdryer (ON COLD) from a distance? - If you don't have one of those ball blower thingies devices for lenses.

Could it be dew water marks on the sensor?

[JimStan]

Dust does not show up as blue and red pixels. But "hot pixels" do ! That is what you need the "dark" files for. They will show up the pixels against a black background. Deep Sky Stacker will take these dark files, and subtract the hot pixels from the image, and you will no longer be seeing them !

Actually, I am looking very hard to see what you are talking about, and it is not readily apparent to me in your submitted image. Are you using "zoom" mode to see them clearer ?

Jim S.

[JB80]

Actually, I am looking very hard to see what you are talking about, and it is not readily apparent to me in your submitted image. Are you using "zoom" mode to see them clearer ?

Jim S.

I can see them easy enough, I have circled what I believe is the problem for those who can't see it straight away.

Unfortunately I have no idea what the cause or the fix is but hopefully I can help by circling the squiggles, there are more too than I circled.

Sorry Peter I can't help more than that.

[FraserClarke]

As Jim says, these are hot pixels which haven't been subtracted properly by the dark (if you used one?). When the stacking software aligns the stars in all the images, things which are fixed on the detector (like hot pixels and dust rings, etc), get moved around in the opposite direction. The squiggle nature is showing up the periodic error and polar misalignment in your mount very nicely