1. A method for generating images in computed tomography using 3D image reconstruction, the method comprising: scanning an examination object by moving a focus on a spiral focal track about the examination object using a conical beam emanating from the focus and using a planar detector for detecting the beam, the detector supplying output data corresponding to the detected radiation; and reconstructing image voxels from the scanned examination object from the output data and reproducing attenuation coefficients of the respective voxel, each image voxel being reconstructed separately from projection data that include a projection angular range of at least 180°, and an approximate weighting taking place for each voxel considered in order to normalize the projection data used relating to the voxel.