210 optional refractor lens 211 mirrors 212 and 213 optical receiver 214 and control circuitry several different techniques may be employed to automatically focus the projection equipment and the present invention is compatible with most of these techniques one method of focusing which is compatible with the preferred embodiment of the present invention reflects an optical signal off the surface of the photoresist layer on the wafer and into an optical receiver which converts the signal into electronic signals used to focus the printer as illustrated in fig1 the optical transmitter 210 transmits an optical signal through an optional refractor block 211 to mirror 212 the mirror 212 reflects the optical signal 230 onto the surface of the photoresist layer at a shallow angle of incidence the optical signal should strike the photoresist layer in the center of the area where the reduced image from the reduction lens is to be focused and the optional refractor block 211 may be used to precisely adjust this position the optical signal then reflects off the surface of the photoresist layer to mirror 213 mirror 213 reflects the optical signal into the optical receiver 214 the optical receiver 214 converts the optical signal into an electronic signal which is fed to a control circuit which inturn is connected to a motor the motor raises and lowers the optical column or the wafer table in some configurations to focus the reduction lens if the projection equipment is out of focus.