This is definitely a problem with the iPhone 4s. I have also experienced this problem, especially in dark photographs. It is worse in bars and clubs, but definitely not because of the smoke. I have also taken pictures out in the open with no smoke present and the problem persists. I don't know about
most people on this site, but the biggest motivating factor in picking this phone over others in its class was the camera, an if this doesn't work right I definitely want to exchange for an android. I have set up an appointment with the geniuses to figure out the problem, but just by reading this forum it looks like a product defect.
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Just to clarify, my phone is black, not white. No plastic cover still on. Cleaned lens and tried with and without case. And yes, my good friend has an iPhone 4 and his pics from last night look better than mine.