Hi Andrew,I don't really understand what you are saying ... I take it there's some software that can be used with manual selection of the best gray to estimate the effect of the optical brightener? i1Profiler? Something else? ArgyllCMS has an algorithm that's described here: file:///H:/bin/Argyll_V1.6.3/doc/FWA.html and in more detail here: http://www.imaging.org/IST/store/epub.cfm?abstrid=22190. Essentially, the software flattens out the characteristic lump in the spectrum, due to FWA, which occurs around 450nm. By looking at the paper white measured by the instrument (which has a known UV content), taking a reading of the reflected white from the illuminant, and measuring the illuminant directly, it can estimate the UV content in the illuminant and with this estimate the FWA correction required for the paper under this particular illuminant. I don't know how well this works.I do have an i1Pro2 which has two light sources, one with no UV, so I should be able to use it to compensate for FWA ... but I made the mistake of buying the i1Basic package so I'm now waiting on delivery of the i1 Publish upgrade (which should hopefully allow me to check this out). However ... mostly this isn't a problem for me because I don't use papers with optical brighteners much.If you look at my 11:15 post today (one before last), I say "I assume that FWA compensation would have the same effect: that is, that if the illuminant has less UV than D50, the blues will be bumped up, if it has more, the blues will be reduced. There should be no effect (or very little) at the green-red side of the spectrum.". When it comes to soft-proofing, my assumption is that one should have two profiles, one with Illumination and FWA compensation, the other without; the choice then is:Print using the profile 'with compensation' and soft-proof with the profile 'without compensation' (as there is no compensation required to the monitor image).Print using the profile 'without compensation' and soft-proof using the profile 'with compensation'.The second option would seem wrong, but if we use the first option then we are attempting to remove or reduce the effect of FWA and the illumination difference to D50 ... which I don't think one should unless we know precisely what illuminant will be used to view the print (which mostly I do not, except for exhibitions). So the second option leaves things as they are (that is, no compensation in the print), but should help to match the soft-proof to the print more accurately (as it should do the exact opposite to the print compensation). Assuming, that is, that I don't have this head-to-tail or worse!I'll check this out with Graeme Gill, once I'm reasonably confident that I understand what I'm talking about. As usual, any help would be most welcome!!Robert[/list]
I don't really understand what you are saying ... I take it there's some software that can be used with manual selection of the best gray to estimate the effect of the optical brightener? i1Profiler? Something else?
Set of targets and software that ships with the iSis (and maybe newer i1Pro?). It's a proprietary X-rite software and visual target solution for adjusting papers and illuminants with respect to OBAs.
