An x-ray apparatus, comprising: an x-ray generator configured to generate x-ray electromagnetic radiation; a visible light generator configured to generate visible electromagnetic radiation; a projection member comprising a material at least partially transparent to visible light, wherein the projection member comprises an image positioned within the path of the visible electromagnetic radiation so as to project a secondary image comprising a shadow defined by the image; a ranging beam configured to deliver a visible light beam at an angle relative to the visible electromagnetic radiation such that the visible light beam intersects at least a portion of the image at a predetermined distance from the ranging beam; characterised in that it further comprises: a first rotatable disk; a first shutter (153,155) at least partially defining a collimation aperture, wherein the first shutter is operably coupled with the first rotatable disk such that rotation of the first rotatable disk moves the first shutter to alter a size of the collimation aperture; a second rotatable disk; and a second shutter (157,159) at least partially defining the collimation aperture, wherein the second shutter is operably coupled with the second rotatable disk such that rotation of the second rotatable disk moves the second shutter to alter a size of the collimation aperture, wherein the apparatus is configured such that the collimation aperture at least partially defines a size of the secondary image, and wherein the apparatus is configured such that the collimation aperture at least partially defines a size of an x-ray target shape delivered by the x-ray generator, wherein the apparatus is further configured such that rotation of the first rotatable disk through a first angle results in movement of the first shutter of a first distance, wherein rotation of the second rotatable disk through the first angle results in movement of the second shutter of a second distance, and wherein the first distance differs from the second distance. an x-ray generator configured to generate x-ray electromagnetic radiation; a visible light generator configured to generate visible electromagnetic radiation; a projection member comprising a material at least partially transparent to visible light, wherein the projection member comprises an image positioned within the path of the visible electromagnetic radiation so as to project a secondary image comprising a shadow defined by the image; a ranging beam configured to deliver a visible light beam at an angle relative to the visible electromagnetic radiation such that the visible light beam intersects at least a portion of the image at a predetermined distance from the ranging beam; characterised in that it further comprises: a first rotatable disk; a first shutter (153,155) at least partially defining a collimation aperture, wherein the first shutter is operably coupled with the first rotatable disk such that rotation of the first rotatable disk moves the first shutter to alter a size of the collimation aperture; a second rotatable disk; and a second shutter (157,159) at least partially defining the collimation aperture, wherein the second shutter is operably coupled with the second rotatable disk such that rotation of the second rotatable disk moves the second shutter to alter a size of the collimation aperture,