A viewing device comprising: a housing; a camera having a zoom lens and a focus lens, a display, a user interface, and a circuit (10, 11, 15) including a processor the processor being adapted to: generate a display including an image of an object of interest, correlate image pixels with object actual physical dimensions, apply an overlay (52, 53, 56, 57) to the display to indicate said correlation, in which the overlay includes at least one cursor (52, 53, 56, 57) displayed to touch the object image and an indication of said physical dimensions, characterized in that, camera characteristics used for said physical dimension calculation are stored in read-only format in said circuit; wherein said characteristics include a plurality of camera zoom lens positions and a plurality of camera focus lens positions, and the processor is adapted to determine an object-camera distance from the focus lens position when fully zoomed-in on the object; wherein the camera is capable of performing continuous zooming, and the processor is adapted to dynamically calculate a pixel-to-scene distance correlation according to an algorithm; wherein said algorithm is: pixels per distance unit = Ae nx, where: A is a coefficient dependent on distance between the object and the camera and a zoom level employed, wherein the value of A is returned from a lookup table by interpolation for a current zoom lens position and the determined object-camera distance x is a value representing zoom lens position, and n is a constant coefficient value for the camera, determined at manufacture. a housing; a camera having a zoom lens and a focus lens, a display, a user interface, and a circuit (10, 11, 15) including a processor the processor being adapted to: generate a display including an image of an object of interest, correlate image pixels with object actual physical dimensions, apply an overlay (52, 53, 56, 57) to the display to indicate said correlation, in which the overlay includes at least one cursor (52, 53, 56, 57) displayed to touch the object image and an indication of said physical dimensions, characterized in that, generate a display including an image of an object of interest, correlate image pixels with object actual physical dimensions, apply an overlay (52, 53, 56, 57) to the display to indicate said correlation, in which the overlay includes at least one cursor (52, 53, 56, 57) displayed to touch the object image and an indication of said physical dimensions, characterized in that, camera characteristics used for said physical dimension calculation are stored in read-only format in said circuit; wherein said characteristics include a plurality of camera zoom lens positions and a plurality of camera focus lens positions, and the processor is adapted to determine an object-camera distance from the focus lens position when fully zoomed-in on the object; wherein the camera is capable of performing continuous zooming, and the processor is adapted to dynamically calculate a pixel-to-scene distance correlation according to an algorithm; wherein said algorithm is: pixels per distance unit = Ae nx, where: A is a coefficient dependent on distance between the object and the camera and a zoom level employed, wherein the value of A is returned from a lookup table by interpolation for a current zoom lens position and the determined object-camera distance x is a value representing zoom lens position, and n is a constant coefficient value for the camera, determined at manufacture. pixels per distance unit = Ae nx, where: A is a coefficient dependent on distance between the object and the camera and a zoom level employed, wherein the value of A is returned from a lookup table by interpolation for a current zoom lens position and the determined object-camera distance x is a value representing zoom lens position, and n is a constant coefficient value for the camera, determined at manufacture. A is a coefficient dependent on distance between the object and the camera and a zoom level employed, wherein the value of A is returned from a lookup table by interpolation for a current zoom lens position and the determined object-camera distance x is a value representing zoom lens position, and n is a constant coefficient value for the camera, determined at manufacture.