This case study presents an overview of the use of online photo-elicitation using inquiry graphics (IGs) to identify threshold concepts (TCs) in Irish social care education by educators/knowledge contributors, students, and graduates. The IG photo-elicitation method was combined with semiotic and TCs theories to form a visual hybrid called threshold graphics. Threshold graphics were researcher- and participant-provided images used to represent uncomfortable or troublesome learning, evaluated as a teaching tool and research method. Online IG photo-elicitation proved successful in accessing the participants' visual sign world, for critical engagement and for revealing conceptual knowledge. The semiotic framework of IGs offered a step-by-step questioning method to identify sign typologies related to TCs within the images. [This content is provided in the format of an e-book.]