One of the features that Apple is touting in its new iPhones is Live Photos. Basically what happens here is that it records a couple of seconds of your subject along with a photo. This means that when you tap on the photo, it will “animate”, thus making your photos more dynamic and interesting.
Unfortunately it also seems to be hampering the way normal photos are taken. According to a report from 9to5Mac, it has been observed that if Live Photos were enabled, the resulting photos you take on your iPhone 6s and 6s Plus will be darker than normal. Turning off Live Photos seems to fix that as you can see in the screenshots above.
So why is this? Is it a bug? Apparently not. To take a Live Photo, the iPhone 6s basically needs to be recording video at 12fps, which in turn prevents the phone’s camera from exposing shots long enough to let more light in, thus generating a darker and potentially granier photo. So by disabling Live Photos, your camera app should go back to functioning as per normal.
We’re not sure if this is something Apple plans to address in a future update, but in case your photos are turning out dark and grainy, this is one way to go about solving it for now.