Ultra wide angle lens the difference is only whether distortion is present or not. However, the shorter the focal length, the more difficult it is to implement rectilinear correction. In fisheye lenses, the visual angle is close to or more than 180 degrees in at least one direction. For example, a "diagonal fish eye" would have a viewing angle of at least 180 degrees within the diagonals of the frame. A "circular fisheye" would represent the image in the form of a circle. Rectilinear ultra-wide angle lenses are used in photography and cinematography sometimes to achieve three-dimensional perspective distortion instead of simply two-dimensional barrel
Less than truckload shipping Less than truckload shipping Less than truckload shipping or less than load (LTL) is the transportation of relatively small freight. The alternatives to LTL carriers are parcel carriers or full truckload carriers. Parcel carriers usually handle small packages and freight that can be broken down into units less than . Full truckload carriers move freight that is loaded into a semi-trailer. Semi-trailers are typically between and require a substantial amount of freight to make such transportation economical. There are several different perspectives as to what is actually considered LTL. Full Truck Load carriers can put anywhere from 2 to 6