Holographic Projection System

A holographic projection system for forming, at a replay plane, a holographic reconstruction of a picture comprising an array of pixels, the system comprising a detector arrangement arranged to detect light received by a first detection area;

• wherein the holographic projection system is arranged to perform an optical alignment process comprising:
• selecting a first pixel of the array of pixels;
• forming a first holographic reconstruction of a first picture, the first picture comprising a primary control region comprising the selected first pixel;
• moving the first holographic reconstruction with respect to the first detection area in a first dimension of the replay plane such that the first holographic reconstruction is moved between a plurality of positions;
• and
• determining a value for a parameter of the light received by the first detection area in each of the plurality of positions and comparing each respective determined parameter value to a threshold condition;
• wherein, if the threshold condition is not met over the plurality of positions, the holographic projection system is arranged to repeat the optical alignment process by:
• selecting a second pixel of the array of pixels that neighbours the first pixel;
• and forming a second holographic reconstruction of a second picture, the second picture comprising a primary control region comprising the second pixel.