This paper describes the addition and benefits of an improved detector model and a radiographic noise model to a previously developed mathematical model of a specific radiographic system. The model intentions are to simulate realistic synthetic radiographs of thin laser welded titanium welds and to act as an X-ray projection kernel in an image analysis algorithm. Both these objectives put high demands on low calculation time and to accomplish this a number of simplifications have been done. An evaluation of the tradeoff when using the simplifications is essential and simulations of specific geometries and the radiographic inspection procedure are used for this purpose. As verification the simulated radiographs are compared to real digital radiographs relevant for the proposed applications.