1. A method of correcting extrafocal radiation of an X-ray tube in image recordings with a computed tomograph, comprising: subjecting measured data, obtained from detector channels of at least one detector row in the computed tomography, to logarithmic manipulation and back projection in order to obtain the image recordings; and subjecting the measured data, before the logarithmic manipulation and back projection, to convolution with a detector-channel-dependent convolution core, derived from a distribution of the extrafocal radiation on at least a first detector channel of at least one of the computed tomograph and a computed tomograph of an identical type.