Challenge image quality - artefacts due to dpr processing?

Started Jan 20, 2013 | Discussions thread
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chrisby
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Challenge image quality - artefacts due to dpr processing?
Jan 20, 2013

I recently uploaded a photo for a challenge entry to my gallery. Checking the quality I was shocked: there are very much artefacts, mostly in the dark areas.

I first thought it was because of my slight adjustment of levels and size reduction, but after loading the orignial I saw the same, even worse. The photos, processed and not processed, are looking perfect in photoshop.

Because I still plan to enter my photo in the challenge and to remain it anonym, I post examples from another challenge, just to show you the effect. Please look at the sky!

http://www.dpreview.com/challenges/Entry.aspx?ID=697421&View=Results&Rows=25

http://www.dpreview.com/challenges/Entry.aspx?ID=697491&View=Results&Rows=25

My two questions:

Is that typical, but why this effect is seen only on a few pictures?

Would you give such pictures lower votes because you think it is a bad PP (what it is not case, because also photos without ANY PP could show this effect)?

Thank you for your thoughts!

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