The lamps these instruments are calibrated against are either PTB, NIST or NRC traceable, within their respective uncertainty budgets, which usually translate into fractions of delta Es. Still not good enough for you? Roger > -----Original Message----- > From: argyllcms-bounce@xxxxxxxxxxxxx [mailto:argyllcms- > bounce@xxxxxxxxxxxxx] On Behalf Of edmund ronald > Sent: 2 octobre 2010 04:50 > To: argyllcms@xxxxxxxxxxxxx > Subject: [argyllcms] Re: ColorMunki measurement drift > > I am afraid there is not really "ONE" reference instrument at this time - > depending on whether you chose PhotoResearch or Minolta or something > else you will get different "references". The best one can really hope for is > that one manufacturer's instruments match between each other. > > That's assuming they are good enough to measure the same at different > points in time. > > Edmund > > On Sat, Oct 2, 2010 at 3:53 AM, Roger Breton <graxx@xxxxxxxxxxxx> wrote: > > Among all the instruments I enumerated, the PR-704 can be a reference > > instrument ? no offence / Roger > > > > > > > > From: argyllcms-bounce@xxxxxxxxxxxxx > > [mailto:argyllcms-bounce@xxxxxxxxxxxxx] > > On Behalf Of János, Tóth F. > > Sent: 1 octobre 2010 21:02 > > > > To: argyllcms@xxxxxxxxxxxxx > > Subject: [argyllcms] Re: ColorMunki measurement drift > > > > > > > > Well, I think we should compare each of those instruments to a much > > better reference instrument (or a reference light source), but not > > between each others. I think it can't tell anything. They will be > > closer to or further from the true but randomly, so you can't tell.