Due to the rolling shutter of the iPhone, you can sometimes distort the photo or create varied amounts of blur across the photo as it is taken.
What is ‘rolling shutter’ you may ask?
In layman’s terms it means that the CCD in the iPhone scans what it is seeing one line at a time from top to bottom. If you are holding the camera still you will never notice the rolling shutter.
On the other hand if you are taking a photo out of a moving car pointing the camera directly at the guardrail, you will see that the image looks slanted.
The live view will look like Jello.
When you take a picture while the object is moving quickly in relation to the iPhone, you will get slanted distortion. In low light this skew is coupled with a slow shutter speed (the time it takes for the camera sensor to scan the entire scene) resulting in some part of the frame turning out blurry while the rest is sharp.
This is what happened with the above picture. You see the blurriness to the left of the frame as I swung right and stopped. Part of the photo was scanned while moving, the last part scanned while stopped. If used on purpose you can get something rather unusual.
The photo above shows extreme Rolling Shutter effects. This was taken while disembarking from a plane at SeaTac Airport.
For most people rolling shutter sucks big time.
In fact it is one of the main complaints of the new Nikon D90 that incorporates Hi-Def video using a bastardized version of the Nikon Live View function.
For us lo-fi individuals, rolling shutter provides a creative restraint.