Microscopy and precise observation are essential skills that are challenging to teach effectively to large numbers of undergraduate biology students. We implemented student-driven digital imaging assignments for microscopy in a large enrollment laboratory for organismal biology. We detail how we promoted student engagement with the material and how we assessed student learning in both formative and summative formats using digital images. Students worked in pairs to collect over 60 digital images of their microscopic observations over the semester and then individually created electronic portfolios, which were submitted for a grade.