Here's what causes a smartphone camera's photos to come out blurry
But what causes blurry photos, anyway? Well, a dirty lens may be the culprit – the glass covering your phone's camera comes in contact with your fingers more often than you think. That's why cleaning your camera before taking photos is a good idea - wipe it with a piece of soft cloth to remove smudge build-ups.
Blurry images could also be caused by your phone's camera failing to focus properly. This might happen when you're taking close-ups against a distant background – the camera might prioritize the background instead of focusing on your subject. Thankfully, we have tap to focus supported by pretty much every modern phone's camera. Use it to aid your camera in focusing at the right spot.
Thirdly, low-light photos may be affected by blur if the user's hands are not perfectly steady while holding the phone. Even the press of the shutter may cause blur if one's not being careful. You see, a photo is not captured instantly. The camera's image sensor has to be exposed to light for a certain period of time, and in low-light situations, this period could be as long as a quarter of a second, if not more. Any movement that occurs during this brief moment will produce some amount of blurring in the image. That's why cameras featuring optical image stabilization are much more effective in such scenarios. OIS won't help if your subject itself is moving, however.