Image sensor defects that develop in field over a camera’s lifetime are at the core of temporal image forensics, as by knowing their onset time a temporal order can be assigned among pieces of evidence. In this context, only defects that have developed within the time interval of the available data set are relevant. The available methods for defect detection, based on regular scene images, aim to identify all present defects (e.g., to conceal them). In this paper, we introduce two novel defect detection techniques. Because of their properties, these methods only detect defects relevant for image age approximation. This is important since defects that do not provide additional age information can negatively affect the process of image age approximation.