A method for adjusting an optical system of an energy beam apparatus by using a mark signal that is obtained by one-dimensionally or two-dimensionally scanning a mark on a sample with an energy beam. Operating a high power Q-switched laser in a frequent on-off mode is highly desirable for laser prostatectomy. The flow path in the coater includes a flow modifier shaped to have the introduced coating first turn upstream relative to the web or roll surface, then turn across a curved surface toward the web or roll and around the flow modifier. The inner end portion is closer to the common axis than the outer end portion, the ramp rising as it moves from the inner end portion toward the outer end portion. These may be premixed with a phenol-formaldehyde resin without microencapsulation to protect the dye from other ink ingredients that have chemistries which are incompatible with that of the dye, in order to obtain photochromic ink formulation with a good shelf life. The hands-free lighting is preferably lighted headgear including hats and includes various accessories for use therewith, such as a protective switch guard associated with hat packaging surrounding an activation switch to prevent inadvertent activation while still allowing intentional actuation thereof.