A radiation therapy device may include: a radiation source that directs a beam to a target volume from at least two opposite directions, a collimator having multiple elements for localizing the treatment beam to generate a radiation-exposure field, wherein an expansion of the collimator elements predetermines a resolution of the radiation-exposure field, and an offset unit affects the irradiation of opposing radiation-exposure fields at an offset such that the two opposing radiation-exposure fields are offset from each other by a fraction of the resolution. Furthermore, a method for generating a resolution enhancement in irradiated radiation-exposure fields may include: generating a first radiation-exposure field using a collimator which delimits a beam emitted from a first spatial direction and generating a second radiation-exposure field using the collimator which delimits a further beam emitted from a second spatial direction, the second radiation-exposure field being offset from the first radiation-exposure field by a fraction of the resolution.
