Provides information about how focused the image is from top to bottom. The focus factor improves decoding performance by ignoring images that are out of focus due to distance or motion. If you are changing the scanning angle of the computer or are scanning 2D bar codes, you should enable both Horizontal Focus Factor and Vertical Focus Factor.
Disable
Data Collection > Specified Scanner > Imager Settings > Optimized Imager Modes > Advanced > Vertical Focus Factor