The distance from which a barcode can be successfully scanned depends heavily on the type of scanner technology, the optical resolution of the imager, and the physical size of the barcode itself. Standard 1D retail laser scanners typically require a close proximity ranging from a few inches up to two feet. However, advanced industrial long-range area imagers and specialized warehouse data-collection terminals equipped with high-performance autofocus optics can read large, high-density barcodes or specialized retro-reflective warehouse rack labels from distances exceeding 15 meters or nearly 50 feet away.