In one aspect, a system for determining field characteristics during the performance of an agricultural operation may include an imaging device configured to capture image data associated with a portion of the field within a field of view of the imaging device. The system may also include an illumination device configured to emit a light directed at the portion of the field within the field of view of the imaging device. Furthermore, a controller of the system may be configured to control an operation of the illumination device such that a light pattern is displayed on a field surface of the field. Moreover, the controller may be configured to receive image data indicative of the displayed light pattern from the imaging device. Additionally, the controller may be configured to determine a field characteristic of the field based on the displayed light pattern.