On 12 October 2010 11:07, Pascal de Bruijn <pmjdebruijn@xxxxxxxxx> wrote: > On Tue, Oct 12, 2010 at 12:01 PM, Sam Berry <samkberry@xxxxxxxxxxxxxx> > wrote: > > I would think, if you are just after the numbers, that remeasuring with > > spotread (which should give you more instantly usable numbers) may be the > > easiest way if you still have the object to measure. > > Spotread will give you numbers relative to 100% reflectance.You can set a > > paper white as a reference in spotread too, which may give you a result > you > > prefer. Not sure of an easy, non-bodged way to do it from an .sp file.... > > Result is XYZ: 29.960414 19.359126 7.067359, D50 Lab: 51.104747 > 49.415136 27.528969 > > That will translate to > > 29.960414 19.359126 7.067359 [XYZ] -> MatrixFwd -> 202.089327 > 79.937153 78.189606 [RGB] > > Which seems like a pastel to me on screen, which it isn't on paper... > Beware that using those numbers will *not* give an exact match from screen to paper unless your screen is calibrated to D50. Using D50 as the reference adapts the white point to the sRGB D65 white point and reduces the red saturation. Without adaptation the RGB numbers are 209,78,64. If neither a D50 or D65 reference white gives you the result you are after, then the chances are either your monitor is poorly calibrated/profiled or your sample viewing light is irregular (ie. not D50/D65). If you want an on screen patch to match your sample, you need to sample your illuminant and use it with spotread, and then use a D65 reference within Bruce's converter, assuming your monitor white is D65. Whether this is what you actually want to do is a different matter.... > Regards, > Pascal de Bruijn > > Sam Berry