Light destribution of headlight beam

An apparatus for determining a projection direction of a light beam emitted from a light source, comprising:

• at least four photoelectric means for converting light received to an electric signal, including a first and a second photoelectric means spaced apart vertically and a third and a fourth photoelectric means spaced apart horizontally;
• holding means for holding each of said photoelectric means individually moveable in a first direction and a second direction normal to said first direction, said first and second directions defining a plane generally perpendicular to the projecting direction of said light beam;
• first indicating means electrically connectable to said first and second photoelectric means for indicating electrical signal output from said first and second photoelectric means;
• second indicating means electrically connectable to said third and fourth electrical signal output for indicating electrical signal output from said third and fourth photoelectric means;
• and
• position indicating means operatively connected to said holding means for indicating a predetermined position of a light pattern of said light beam, the indication of said position indicating means indicating the projecting direction of said light beam;
• wherein said four photoelectric means are each moveable relative to each other in said first and second direction when said projecting direction is being indicated.