Message
Re: [colorvision_group] Prob profiling IJA MicroCeramic Luster (long, for ColorVision tech guys)
2007-11-20 by CDTobie@aol.com
In a message dated 11/20/07 12:33:23 AM, dealy663@... writes:
I printed the 225 patch target along with the grays last night and let
the dry 24hours. When I read the color target I placed it over two
unprinted sheets of micro ceramic luster, and after doing the reading
it showed a b value of something like -91 in the Ref White dialog box!
No need for a long post following that. This would indicate that your spectro simply can't handle the degree of optical brighteners in the paper. First, clean your white tile with some Windex or Rubbing Alcohol on a dark colored cloth rag (light or bright rags may contain optical brighteners, and we don't want to add any of those to the tile). Next recalibrate to the white tile, once the tile is dry, and reread paper white again. If its still a large negative b* number, then put in a support ticket at the Tech Support Queue at the colorvision.com website, stating this, and they will send you a replacement spectro. This doesn't mean your current spectro is in any way suspect on papers where it can handle the paper white value, so any measurement sets you've already taken where the white is white (not Cyan) are fine, you'll just need a replacement spectro before you can measure highly whitened media.
C. David Tobie
Product Technology Manager
Digital Imaging & Home Theater
Datacolor Inc.
CDTobie@...
www.datacolor.com/spyder3
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