RE: Correction: Spectrocam vs Spectroscan
RE: Correction: Spectrocam vs Spectroscan
- Subject: RE: Correction: Spectrocam vs Spectroscan
- From: Raymond Cheydleur <email@hidden>
- Date: Thu, 21 Dec 2000 10:01:25 -0500
I'm getting ready for flames, but here goes-
I found the results mildly interesting, and somewhat amusing.
Targets measured a week apart?
How old was the target when first measured?
Which instrument was used first?
What backing was used for each?
How many times what the target read by each instrument?
If the same instrument read the target twice what would the variances be?
These are just the first questions that come to mind.
I'm often called on to check measurement data and compare instruments and
these are just some of the questions that come into play. Without very tight
control, this is just a little better than a subjective evaluation of the
results after running through software. When training people in how to do
testing, I often find that until they learn to control the variables, they
can use a laboratory quality instrument and do the same tests twice and get
De values in the 2-6 or higher range for some measurements. Using the same
instrument, but controlling the variables, all values will be below 1 De.
When comparing any instruments knowing first the repeatability of the
instrument, on the samples being measured, and then and only then doing a
comparison to another instrument makes sense. A while back I took one
instrument from a new company and found that on photo glossy inkjet
material, it was pretty good, less than 2 De average from standard values.
On plain bond paper however, the De shot up to 6 average from standard
values.
RayC
Raymond Cheydleur, Lead Application Support Specialist,
Imaging and Graphic Arts, Developer Support
X-Rite Incorporated
Application Support 888-826-3046, Option 1
Customer Support 888-826-3059
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