Therefore, the transparency is placed face up (toward the mirror and focusing lens), in contrast with a 35mm slide projector or film projector (which lack such a mirror) where the slide's image is non-reversed on the side opposite the focusing lens.Ī related invention for enlarging transparent images is the solar camera, but a similar purpose for opaque materials is served by the epidiascope.īecause the focusing lens (typically less than 10 cm in diameter) is much smaller than the transparency, a crucial role is played by the optical condenser which illuminates the transparency. That mirror also accomplishes a reversal of the image in order that the image projected onto the screen corresponds to that of the slide as seen by the presenter looking down at it, rather than a mirror image thereof.

For the latter purpose, the projector includes a mirror just before or after the focusing lens to fold the optical system toward the horizontal. However some differences are necessitated by the much larger size of the transparencies used (generally the size of a printed page), and the requirement that the transparency be placed face up (and readable to the presenter). Educational Technology can provide support and training on document cameras.An overhead projector works on the same principle as a slide projector, in which a focusing lens projects light from an illuminated slide onto a projection screen where a real image is formed.

Most academic buildings have document cameras available.

Digitized media will work best with Epson BrightLinks or Apple TV’s AirPlay.

Things to Consider Before Using a Document Camera

Zoom in on specific passages or work to focus and promote student engagement.

Present articles, magazines, art, slides etc.

Show 3 dimensional media from various angles.

Backlight for slides and transparencies.

They are similar in function to overhead projectors, but with greatly improved capabilities such as zooming in or out, adjustable light levels (ideal for slides), and various viewing angles (ideal for three-dimensional objects). Document Cameras are digital video cameras with a bed or tray to place media on for projection purposes in a classroom setting.

Overhead document camera