A document camera, despite its name, is not solely for photographing documents. One of its main features is that it is digital, although when it was first developed in the late 1980s, analog video output was standard. Able to capture images of three-dimensional and two-dimensional items in real time for display or projection, a document camera’s images — which may be still photographs or video — can also be saved to a computer for further consultation or use. A document camera may also be known as a visualizer, visualiser, digital document camera, or digital visual presenter.
From appearance alone, the document camera may seem to bear some resemblance to an overhead projector. Whereas an overhead projector can only properly represent images on transparencies, and requires documents to be changed to this format in order to display, the document camera does not have this requirement. Instead, documents and objects can be used as is. A test tube containing fruit flies or a gun with a fingerprint can be displayed as easily as an historical document or a watercolor painting, for example.
Uses for a document camera include the 21st century courtroom. The document camera is an important element of courtroom technology, and the images are either shown to all on a projection screen, or LCD flat screen panels are provided to each juror to inspect items up-close. The use of courtroom technology such as this has been found to make court cases able to be handled more efficiently. Document cameras are also used in education much as the overhead projector had been — to help everyone in a lecture hall or classroom be able to see small items clearly and simultaneously. Distance education has also benefited from the document camera, as have business people who may use them for business presentations in which three-dimensional items, as well as documents, are important to share with a large number and in real time.
At least some document cameras are compatible with whiteboards, interactive touchscreens that allow annotation of a projected image. This benefits users in all the venues mentioned. A teacher can add student’s observations to an image; an expert witness in a courtroom can identify the salient features of a piece of evidence; the marketer can focus attention on key aspects of a product presentation. The fact that document cameras can show events unfolding in real time also facilitates lecture demonstrations of very fine or small events that would not otherwise be visible, including, for example, the changes that occur in a chemical reaction or a demonstration of Japanese calligraphy. Additionally, if there is zoom capacity, the document camera can function as a microscope.