Operation of an opaque projector

The opaque projector is a little known term used in the French language. For many, it is the modern version of the magic lantern that is now called an episcope or epidiascope.

These two designations designate two devices that differ in a few details. But, overall, they are devices that function in the same way, that is, they project bright light directly onto a non-transparent object. The light is reflected from the object and through a series of mirrors or prisms and a lens. This allows the user to magnify and transfer an image from a small opaque source to a larger surface such as a whiteboard or canvas.

The magic lantern, a beautiful invention

Actually, if we're used to it.use the episcope or the epidiascope, the famous magic lantern has not yet lost its "magic" side. Indeed, it is the first projector in the world. It projects light through glass slides with painted images. As printing evolved, manufacturers were able to produce glass slides with printed rather than painted images. These projectors worked by transmitting light through a transparent object. This transmitted light is known as diascopic lighting.

The episcope, an improved magic lantern

An episcope or episcopic projector is a device that uses the reflection of light to project an image onto a surface. The projector projects bright light onto the opaque object. The light is directed by several mirrors or prisms towards the projection lens. However, the focus of the lens can be adjusted to change the size of the image.

The first episcopes were used to view postcard images, magazine images, advertising cards and even images supplied by the projector manufacturer. An episcope, or opaque projector can even be used to view small three-dimensional objects such as coins, leaves or insects.

The epidiascope, an improved episcope

The episcope is a revolution compared to the magic lantern. But the epidiascope is even better because it combines the ability to view transparent and opaque objects in one device. An epidiascope allows the user to view both slides and opaque objects.

The teachers and professors appreciate the opportunity to project pages from books, printed materials and photographs as well as slides or transparencies so that the entire audience can see the project object. However, as this technology is still analogue, most modern classrooms are now equipped with a digital projector connected to a computer. However, epidiascopes are still considered to be devices that have advanced education.

Episcope and epidiascope used in art

Unlike an overhead or slide projector, an opaque projector (episcope or epidiascope) does not require you to first transfer your image onto something transparent. It allows you to work directly from a photo. This ability has made opaque projectors very popular with artists in the photorealism movement.

The artist can take a picture of what he or she would like to draw or paint on a larger surface. As long as the photograph can fit in the opaque projector, the artist can enlarge it on a canvas or other surface for drawing and painting. Some artists even use this method to reproduce images on a wall to paint a pattern.