The best conditions for an undistorted radiographic image occurs when:

For achieving an undistorted radiographic image, it is important that the object plane—the plane of the object being imaged—and the image plane—the plane of the receptor that captures the image—are parallel to each other. When these planes are parallel, the rays of radiation travel in a uniform manner from the object to the receptor, producing a clear and accurate representation without elongation or foreshortening of the image.

When the object and image planes are not parallel—such as when they are angled—this can lead to distortions. The positioning of the receptor and object critically influences the geometry of the resulting image. An object being larger than the receptor can also lead to parts of the object being cut off and not visible in the finished image, which contributes to distortion rather than clarity. Furthermore, rotating the receptor can disrupt the alignment necessary for a true representation of the object being imaged. Thus, maintaining the parallel orientation of the object and image planes is essential for an undistorted radiographic image.