TOPIC: Computers and Graphics Cards.

Last Update 02 July 2005

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General remarks (MBS)

No specific information found in searches. Hardware may be Mac or PC, but only PC considered here. The process of profiling a display system involves both the projector and the driving PC (or other hardware). Projector: See comments, but projectors are be designed for many purposes, and may include special setup for each. Dynamic colour adjustment setup should be avoided as the projector may modify each image. Static setup is likely to be sRGB, and a projector should only be chosen if it includes this setting. Note that sRGB is similar to the colour gamut of a CRT monitor, is the default for web, and is likely to be assumed if no profile is included with a data file. Having set sRBG, the projector would still have brightness and contrast - as does a monitor - and these are used with s/w like Adobe Gamma. Graphics: It is commonly thought that a data projector needs to be driven by a laptop PC, but that is quite wrong. Any PC is entirely satisfactory. Driving a projector is a low demand application. and the PC can be very low spec. Second hand PCs can be picked up very cheaply, and no monitor is required! Simpler PCs may have the graphics chip embedded on the motherboard, but a specialist graphics card is better. As images are static, the card does not have to be particularly powerful, and a new card may cost only £30. Connection will normally be by an analog VGA (15pin) cable, as graphics cards with DVI connections are unusual. Some projectors are now fitted with DVI connectors: ensure that connection is possible using an adapter cable. Setup Notes: Apart from initial setting on the projector of brightness (actually the dark point) and contrast (actually the white point), the remainder of any profiling occurs at the level of the graphics card. Therefore, the ‘profile’ applies only to the exact combination of PC and projector, and strictly also the display screen and environment. It is incorrect to describe this only as ‘profiling the projector’. Because of the required integration between graphics card and projector for good imaging standardisation, systems which allow the projector to take data from a card reader or over the network may not allow for accurate setup. These features, which sound interesting and useful - and are for non-critical applications - may not be adequate for PDI events.