The aim was to investigate how a reflective tool, the T-CoRe, in combination with annotated self-recorded videos and reflective writing, could be used to capture student teachers' knowledge of digital technology use in their teaching. The authors used both a quantitative and a qualitative method to explore how 87 secondary science student teachers demonstrate their use of digital technologies in their teaching. The student teachers' video annotations, alongside a written reflection of critical incidents in their teaching, constituted data for the analysis. The analysis identified technology knowledge-dependent components in relation to the TPACK framework. The outcomes suggest that providing student teachers with a reflective tool such as the T-CoRe in combination with annotated self-recorded videos has the potential to make visible aspects of their TPACK. This research proposes a method for teacher education that works to improve the way that student teachers are prepared for using digital technology.