A light box is a tool designed for artists that consists of a backlit piece of plexiglass or frosted glass. Many visual artists use these devices in their daily work for things like looking at photographic negatives and tracing. Art supply stores sell a variety of boxes, and it is also relatively easy to make one at home, for people who need to craft a custom version.
Another term for this device is a light table, and large ones may be mounted on adjustable legs and a swivel, creating a large backlit workspace that can be rotated to various angles for comfort. Sizes and construction techniques vary. A light table may be made small with a lightweight aluminum frame so that it is portable, or it may be quite large with a heavy wooden frame, intended for stationary work.
Usually, a light box is distinguished from a light table because it is much more portable and it lacks legs. In some cases, one can be very large, making it technically difficult to move, while in other instances, it may be designed around a lightweight briefcase or tablet so that it can easily be ported from place to place. A box tends to be substantially less expensive than a table, since it does not have a complex framework of legs.
The placement of the lights in the device is very important, since the goal is to achieve even, crisp lighting without hot spots. Diffusers and multiple lights are often used to accomplish this, and the glass or plexiglass is usually fogged or shaded to reduce glare from the lights underneath. The whole assembly is enclosed in a sturdy frame, which often features drawers or divots for storing tools.
To make a light box at home, an artist will need to be able to build a framework to hold the plexiglass in. Metal picture frames work well for this purpose, as long as the artist is able to mount legs to them so that the plexiglass will be elevated. Next, a bank of lights to go behind the plexiglass must be arranged, and sides should be installed to prevent light bleeds. The lights can be anchored to a sturdy backing, such as plywood, to make the device movable.
This term is also used by photographers to refer to a small, custom built box for photographing objects under controlled lighting conditions. These light boxes are used by professional photographers to create clean, controlled environments that can be endlessly manipulated. Different backdrops can be used for specific effects, and the lighting can be altered for varying looks. For macro photography, this is a crucial tool.