A method for controlling an optical retarder for controlling the retardance of light passing therethrough along a first eigen-axis thereof relative to a second eigen-axis thereof in response to the application of signal thereto, said method comprising: (a) supplying a signal to said retarder to control its retardance; (b) changing said retardance from a first retardance to a second retardance by causing said signal to change, in a direction to move toward said second retardance, from a first amplitude which is required for said first retardance to a second amplitude, beyond a third which is required for said second retardance, for a period of time; and (c) thereafter causing said signal to change to said third amplitude required for said second retardance. view more