Ethical concerns in the digital domain are growing with the extremely fast evolution of technology and the increasing scale at which software is deployed, potentially affecting our societies globally. It is crucial that engineers evaluate more systematically the impacts their solutions can have on individuals, groups, societies and the environment. Ethical risk analysis is one of the approaches that can help reduce "ethical debt", the unpaid cost generated by ethically problematic technical solutions. However, previous research has identified that novices struggle with the identification of risks and their mitigation. Our contribution is a visual tool, the Digital Ethics Canvas, specifically designed to help engineers scan digital solutions for a range of ethical risks with six "lenses": beneficence, non-maleficence, privacy, fairness, sustainability and empowerment. In this paper, we present the literature background behind the design of this tool. We also report on preliminary evaluations of the canvas with novices (N=26) and experts (N=16) showing that the tool is perceived as practical and useful, with positive utility judgements from participants.