Optical camera systems for nondestructive internal inspection of online, operating power generation turbines, including gas turbine combustor and turbine sections that are at high operating temperatures in the range of over 600° C. (1112° F.). The system includes one or more temperature and vibration-compensating lens systems in the optical tube mount. The lens is circumferentially retained within a lens mount, with a mounting ring in contact with only the lens axial face. A biasing element exerts axially oriented biasing force on the first lens face through the first mounting ring, allowing for mount flexure in response to operational turbine vibration and temperature changes. The lens mount is advantageously combined with aspheric lenses capable of withstanding continuous operating temperatures above 600° C. The aspheric lenses, alone or in combination with spherical lenses, establish a wider field of view, and require fewer lenses in combination than lens mounts incorporating only spherical lenses.