Projection display apparatus having a correlation table that stores the correlation between an external condition and the value of power supplied to a light source

A projection display apparatus comprising:

• a light source power changing unit changing the value of power supplied to a projecting light source;
• a storage medium for storing an external condition/light source supplied power correlation table that stores the correlation between an external condition and the value of power supplied to said light source that is set up corresponding to the external condition;
• an external condition information acquiring unit acquiring an ambient external condition;
• and
• a light source power control unit which acquires the value of power supplied to the light source corresponding to the external condition acquired by said external condition information acquiring unit, from said external condition/light source supplied power correlation table, and which controls said light source power changing unit so as to produce the acquired value of power that is supplied.