The performance of two newly derived LCD-projector characterisation models has been tested for four liquid crystal based displays – two LC projectors and two LC flat panels. Data measured from a series of test colours, indicated that all LC-based displays showed similar characteristics, including an S-shaped tone characteristic curve and poor channel chromaticity constancy. It is proved that the new characterisation models based on a hyperbolic function fit the tone curve very accurately with only four coefficients per channel for any kind of LC displays. In addition it is shown that the first derivative of the function provides a means of accurate correction of the chromaticity variation.