Artifacts in jpeg but not in RAW

I have adjusted the exposure on the original raw image with +3 stops.
I know it's a lot!
Added sharpening to bring out the stars.
The foreground is a bit out of focus due to my poor eye vision due to laser surgery earlier this month...

But when I saved in 8bit jpeg it showed the artifacts.
Is must be the processing that causes this?
It was saved at max size

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What was the image quality you were set to?

And, do the artifacts show when viewing at enlarged sizes?

tonylong wrote in post #11536797
What was the image quality you were set to?
12
And, do the artifacts show when viewing at enlarged sizes?

yes, but this image also have lots of noise in it

What app was used to sharpen? It looks like ringing from some funky sharpening method.

ArcticShooter wrote in post #11536845
yes, but this image also have lots of noise in it

Heh! That comes from raising the exposure by 3 stops! You might want to try an alternative approach to boosting the stars, unless you are after that brightened/noisy sky -- maybe noise reduction will ease the pain there.

tonylong wrote in post #11537161
Heh! That comes from raising the exposure by 3 stops! You might want to try an alternative approach to boosting the stars, unless you are after that brightened/noisy sky -- maybe noise reduction will ease the pain there.

Any ideas on what approach? I don't need the sky so bright but I want the meteors to show

Here is my 2nd try.

IMAGE LINK: http://www.flickr.com …/articshooter/5​306093447/

First looks like moiré. Is it visible at 100% view?

Probably caused by pattern noise at just the wrong frequency.

René Damkot wrote in post #11540486
First looks like moiré. Is it visible at 100% view?

Probably caused by pattern noise at just the wrong frequency.

Yes it is visible at 50%. At 100% the noise overtaking everything so it difficult to see.
I am quite happy with the newest version