Photographic method of recording radiation fields using the localizer light for illumination

By interposing a camera with a fish-eye lens between the collimator and the illuminated field, radiotherapy ports can be recorded using the localizer light for illumination. An acrylic mold of the camera was used to maintain alignment and immobilization during the necessarily long exposures. The authors consider this a very objective and accurate method of recording the topography of radiation ports.