Re: Photospectometer values/ real objects
Re: Photospectometer values/ real objects
- Subject: Re: Photospectometer values/ real objects
- From: Chris Cox <email@hidden>
- Date: Fri, 8 Jun 2001 13:18:24 -0700
Message: 14
Date: Fri, 08 Jun 2001 08:32:08 -0400
From: Paul Guba <email@hidden>
To: "email@hidden" <email@hidden>
Subject: Photospectometer values/ real objects
Now I have spectrostar spectroscan works well for making profiles. Now
using there software I can measure flat artwork and I am given a set of
values. These being RGB LAB and CMYK densities as I recall. Am I only
to trust the LAB values? I ask because lets say I am comparing a
measured printed value to a photoshop file. Will a difference in RGB
spaces effect values read? Say perhaps the meter bases its RGB values
on one space and my file is in another. It must because as I convert
spaces the values change. Would the not the LAB values also be subject
to this? If the two were using different lab spaces. I figure there
must be a standard lab space for measurement for these devices; at least
I hope. So what would it be and is it the same as photoshop.
LAB values are absolute (as long as you have the same whitepoint -
most products have now settled on D50).
RGB and CMYK values will vary depending on the profile used.
To match the results in Photoshop, you would have to use the same
profile, same intent, and probably the same CMM.
Yes, you should just use the LAB values.
Chris