When adding a raster to the map in ArcMap, ArcGIS uses available metadata and statistic information to optimally render rasters. By default, the added raster dataset is rendered with the Standard Deviation stretch type.
In some cases, the user's raster imagery data is already processed and when the stretch type is applied, the raster become over-stretched. Overstretching often causes the raster to appear faded, or 'bleached-out'. Therefore, in some situations, the stretch is not appropriate.