Colour Light Output (CLO), or colour brightness, is a new measurement of projector picture quality developed by Lumita in 2007 to help consumers assess the ability of projectors to deliver consistently rich and vivid colours.

Based on the existing industry-standard test method, CLO, like brightness, is reported in lumens. CLO specifies a projector’s performance in the delivery of the primary – red, green, blue – colours of light, according to Lumita’s description.

“All video, DVD, HD, digital camera and computer signals are encoded in the RGB colour space. CLO measures the output brightness of the three colours red, green and blue. If a projector can produce red, green and blue brightness equal in lumens to the brightness of white, it can reproduce true colour the way it was intended. If the CLO does not equal the White Light Output (WLO) then colour images will appear dark, washed out and less accurate,” Lumita says.

Epson Visual Imaging business manager Bruce Bealby says it is critically important that consumers compare the CLO of projectors when buying because colour is a key indicator of picture quality. CLO is an objective way of understanding which projector of equivalent WLO, or brightness, will deliver the richest and most vibrant colours.

“CLO provides users with a simple and accurate way to evaluate a projector’s colour performance, allowing them to make better buying decisions. If CLO measured in lumens equals WLO in lumens then the projector will have optimal colour performance. This means rich and vivid colours along with the deep blacks and bright whites,” Bruce says.

For example, a projector with WLO of 1,800 lumens and CLO of 1,800 lumens will deliver optimal picture quality in its class, while a projector with WLO of 1,800 lumens and CLO of 900 lumens will have poor colour performance.

The first Epson projectors released in Australia to specify CLO will be new high definition digital home theatre projectors.

The 3LCD consortium has also announced that Sony will also specify CLO for its projectors.