1. A method for determining an object function from projections of the object acquired from different projection directions by means of an iterative reconstruction algorithm, in which an iteration cycle comprises the following: determination of a projection q i by forward-projection of an approximation image I i−1 in the projection direction &agr; gi of an actually acquired projection p i ; determination of corrective information from the differences between the projections p i and q i ; determination of a new approximation image I i from the approximation image I i−1 and the back-projected corrective information; definition of a new projection p i with the projection direction &agr; gi which differs, at least by approximation, by the angle &agr; g &equals;g·&agr; max from the previous projection direction &agr; gi, &agr; max representing the entire angular range used in creating the projections, and g representing the ratio of the golden section; and execution of the iteration cycle until an abort condition is fulfilled.