Photographs of objects are ubiquitous in the work and presentation of museums, whether in collection-management infrastructure or in Web-based communication. This article examines the use of images in these settings and traces how they function as interfaces and tools in the production of museum knowledge. Because images are not only the main material presented but also become multilayered objects on which to act in order to access or produce knowledge, they play a key role in the involvement of users with museums. This development is analyzed in the context of the Tropenmuseum (an ethnographic museum in Amsterdam, the Netherlands) based on an ethnographic study of visual practices at and about the museum. Drawing on science and technology studies and new media studies, our theoretically driven analysis demonstrates how images as interfaces provide networked contexts for museum knowledge. The various dimensions of images as interfaces in museums are explored through the questions: How are users engaged by these interfaces? Which skills and strategies are needed for this engagement? What are the consequences of visually mediated interfaces for users of digital knowledge in/about/from museums, archives, and other collections? These developments are discussed in terms of their consequences for how museums view their role.