A video document camera is a device that is used to display a larger version of a document so that a group of people can see it. The device is pointed at a document and then the document can be shown on a projector or monitor behind the device. Teachers often use video document cameras in their classrooms.
A video document camera can come in desktop or portable lightweight models. Desktop models generally are meant to be kept stationary, such as on top of a desk or on another flat, supportive piece of furniture. Portable lightweight models can be used on desks as well but are light enough to be moved with frequency. A teacher who travels from one classroom to the next or teachers who share one video document camera might prefer to use a portable lightweight model, because it easily can be moved and set up again.
Older versions of video document cameras operate like video cameras but with flexible necks or goose-necks. The neck, with a lens at the end, points at a document and then the document is displayed in real-time. Newer versions are capable of this same feat but also have modern features such as being able to take a snapshot of a document and have it recalled for future use. This feature often is called "image freeze" and can come bundled together with a zooming capability. Teachers might be more inclined to appreciate the image freeze function over the zooming one because, in the classroom, whole documents can be displayed without much use for zooming.
The modern video document camera typically comes in two forms: extended graphics array (XGA) and super video graphics array (SVGA). An XGA video document camera is known for its high-resolution rectangular images, and the SVGA displays lower-resolution square images. To choose between these video document camera types, teachers will have to assess their needs. They also should know that their decision can also be effected by the type of device they have to display their images. Certain projectors or monitors are capable of displaying only one type of image.
Generally, when consumers shop for a video document camera, they tend to weigh the portability, image resolution, lens optic and power features of devices before deciding on one. Many teachers also look for ease-of-use, meaning that they are apt to choose a device with controls and buttons that are easy to manipulate. Auto-focus is a popular video document camera feature among teachers because it doesn't require that a teacher stop the lesson and manually focus the image of a document.