Bob, I don't deny everyone's point of view on what works and what's best. My question is why attaining "absolute accuracy" is so important when even the most expensive instruments will never yield, to my experience, a visual match to any proofs viewed in a "D50" light booth, "out-of-the box"? Roger -----Original Message----- From: colorsync-users-bounces+graxx=videotron.ca@lists.apple.com [mailto:colorsync-users-bounces+graxx=videotron.ca@lists.apple.com] On Behalf Of Bob Frost Sent: August-20-11 1:24 PM To: Derek Lambert; colorsync-users@lists.apple.com Subject: Re: Colorimeters and third-party developer support (Tom Lianza) Here are Karl Lang's thoughts on that subject - http://www.lumita.com/site_media/work/whitepapers/files/xrite-wp-3a.pdf "In all the cases above we have been discussing expensive instruments that are designed to measure "any" light source. In the unique case of display calibration we often know exactly what kinds of spectra we are going to measure. As an example, let's say we know we are going to measure a Sony CRT. All Sony CRTs use the same three phosphors (one red, one green and one blue) known collectively as the P-22 phosphor set. Variation of the spectra from these phosphors is slight. If we use these spectra at the factory when we calibrate our colorimeter, the colorimeter will have incredible accuracy measuring a Sony display, far better than any spectroradiometer at 10X the price. An interesting advantage of this kind of "purpose built" colorimeter is it does not need to have filters that are near perfect XYZ simulators. All you need are simple RGB filters that can discriminate very well between the three primary phosphors. If you know the source primaries you are going to measure, you can build a very accurate device for an extremely small amount of money. I have worked with colorimeters that cost less than $100 to build that rival the accuracy of a $20,000 spectroradiometer when used on the display they were designed for. When a colorimeter is calibrated to the source primaries of a display with a calibration matrix. The accuracy of the colorimeter on that type of display is greatly increased. The worst case accuracy of this type of purpose built colorimeter can not be matched with a spectroradiometer anywhere near the price. In fact you would have to spend 100 times as much to achieve this accuracy with a spectroradiometer." Eizo actually give some figures in their comparison of their built-in colorimeter with two unnamed colorimeters and a spectrophotometer. - http://www.eizo.co.uk/accuracy_and_advantages_of_the_coloredge_cg245w tables and graphs on pages 6,7, and 8. Bob Frost -------------------------------------------------- From: "Derek Lambert" <csync@colorforest.net>
Really. How much better result will you get with custom device that you can use with only one monitor? 5%? 10%? 50%?
Or how many delta e?
Maybe it is just a marketing hype from NEC or HP? Do you have a scientific results that your custom device is way better than retail device with basiccolor or coloreyes?
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