An image projection apparatus is disclosed which is capable of correcting defocusing due to changes of the temperature of a projection lens, which are caused by various factors. SN2 having an activity for degrading polycyclic aromatic hydrocarbon, a bioremediation process of polycyclic aromatic hydrocarbon contaminants, comprising contacting a microbial strain Alteromonas sp. The electromagnetic perturbation may also be used to tune microwave devices such as filters, resonators, and oscillators. Search bins corrupted by under-compensated interference are pre-calculated and discarded. From the deviation map, an amount of actinic radiation needed to be attenuated to compensate for the critical dimension deviation from the target dimension is determined for each of the regions of the photomask.