That's known issue, and there is one quite lengthy thread on official Google groups (if you are talking about when shooting in low light, right?).
Google is aware of it. They even contacted few of use to recreate this issue and send a bug report to them, and that was like 2 months ago.
This happened after 4.4.1/4.4.2 update affecting all users (as far as I know).
Edit: Here's the link for that thread: https://productforums.google.com/for...U/wsUpKaxQ05EJ
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