Chris Chinnock of Insight Media gave more details about the testing of solid state projectors that it carried out to help get a sense of what users thought of the new ColorSpark technology, side by side with existing systems.
The firm set up a number of different projectors with hybrid (LED & Laser), laser phosphor and LED light sources alongside the Philips prototype, although the projector details were hidden from respondents. They were all set up to display in an sRGB mode, which provides more accurate colour, but reduces brightness significantly. All projectors showed the same images and used the same matt white screens.
The room was lit and this reduced contrast, which when measured turned out to be proportional to the lumen output from the different devices.
The colour of the blues was consistent, but the red and greens varied, as did the white points, although they were all nominally 6500K. Just because you have a big gamut it doesn’t mean that the image color is accurate, Chinnock added. There was a mixture of images in which it was thought people would have a good idea of correct colours. One of the questions was “what is the most pleasing colour”? There were some differences seen between the views of the most accurate and the most pleasing.
303 people were found to try the survey which took place in Turnhout, Belgium.
Insight checked if viewers were colour blind and the result from those that reported themselves to be colour blind was more or less the same as from the non-colour blind. The HK effect was apparent, with reported perception different from the measurement.
Projector C (laser phosphor) had a smaller red gamut and that led to lower accuracy score. Some colours were just not possible.
There was a difference between the most pleasing and the most accurate. B (the Philips HLD) won the subjective best contrast (8:1 measured), although C (laser phosphor) had higher measured contrast.
There was a big difference between the “marketing” and measured lumens. Switching to sRGB then drops the brightness again, so that the actual brightness on the screen was a long way from the brochure numbers.
A white paper is available for download
