A common problem for DSLR and other CMOS sensor-based cameras is that they typically have a lag time between scanning lines of video. Due to the time lag between scans, not all parts of the image are recorded at the same time, causing rolling shutter distortions. These distortions can occur when the camera or subject is moving.
The Rolling Shutter Repair effect in Premiere Pro can be used to remove these distortion artifacts.
After applying the effect, the following properties are available:
Rolling Shutter Rate: Specifies the percentage of the frame rate which is the scan time. DSLRs seem are in the 50-70% range, and iPhone is close to 100%. Adjust the Rolling Shutter Rate until distorted lines become vertical.
Scan Direction: Specifies the direction that the rolling shutter scan takes place. Most cameras scan the sensor top-to-bottom. With a smartphone, you can operate a camera upside down or rotated, which would require a different scan direction.
Method: Indicates if optical-flow analysis and pixel-motion retiming are used to generate the unwarped frames (Pixel Motion), or if a sparse point-tracking and warping method can be used (Warp).
Detailed Analysis: Performs a more detailed point-analysis in the warp. Available when using the Warp method.
Pixel Motion Detail: Specifies how detailed the optical-flow vector field computation can be. Available when using the Pixel Motion method.
Although the Warp Stabilizer effect has a rolling shutter repair effect within it, the stand-alone version has more controls. There are also times when you want to repair a rolling shutter problem, but you do not need to stabilize the shot.