The Loreo 3D Lens in a Cap is a split frame beam splitter which mounts directly to the camera body. Once in place you effectively take two shots every time, which are adjusted automatically to produce a 3D effect when viewed through a conventional 3D viewer. Priced at around $93.00 for digital SLRs.
For the technically minded the 3D Cap has a matched pair of focusing lenses, focusing range from one meter to infinity. F/11 lenses, focal length 38 mm. The 3D Lens in Cap is a brand new design. It forms a 3D effect by transposing two images. Beam splitters designed in the 1960s for SLR cameras have a pronounced keystone effect. The 3D Lens in a Cap retains a slight keystone effect, almost imperceptible without the use of a grid. This was introduced under controlled conditions as a compromise to give the viewfinder a brighter image and to allow the TTL exposure system to function. It is a self-contained, integrated beamsplitter and lens system that mounts directly onto the camera body and does not need any supporting lens.