matthew ward wrote: > When you measure the 'same' patch from a different > print, you get a different answer. How different depends on the > quality of the printer etc etc. An average of the two is a more > 'accurate' answer than each answer individually.
Exactly! The thing about desktop printers is that they are not stable. They may not vary much but they do vary. A delta E difference of 0.4 on neutral grey matter can easily be detected by the human eye. I've conducted a few tests where I've printed the same target twice a day for a few weeks, whenever possible and measured these. Of each measurement of the same target there's a very small (negligible) deviance which can be attributed to spectrophotometer temperature, dust or problems with material stability. However the different prints can vary with a delta E of up to 6 (0.6 on some neutrals), depending on when it was printed. None of the prints are as close to each other as the two same measurements for the same target. The short story is, the more print samples you average, the closer you will get to your printer's mean/average state. If you only measure one set of patches, and your printer is in the "average" state the profile will be great. If not, it wont be. And for Bob Smith: Measuretool, part of ProfileMaker 4.1.5 can be used to average Eye One measurements (it's free in version 4, but needs a dongle for version 5). It used to be a free download - see if you can still download it from GM's website. And is is very easy and very fast to average profiles... Best Regards Thomas Holm / Pixl ApS - Photographer & Colour Management Consultant - Adobe Certified Training Provider in Photoshop� - Apple Solutions Expert - Color Management - Imacon Authorized Scanner Training Facility - Remote Profiling Service (Output ICC profiles) - Seminars speaker and tutor on CM and Digital Imaging etc. - Home Page: www.pixl.dk � E-mail: [EMAIL PROTECTED] -- =============================================================== GO TO http://www.prodig.org for ~ GUIDELINES ~ un/SUBSCRIBING ~ ITEMS for SALE
