Re: differences between colorimeter & spectrophotometer
Re: differences between colorimeter & spectrophotometer
- Subject: Re: differences between colorimeter & spectrophotometer
- From: "Roger Breton" <email@hidden>
- Date: Fri, 5 Oct 2001 08:57:37 -0400
Compared to a spectrophotmeter in reflective mode, can a colorimeter in
emissive mode report 'absolute XYZ colorimetry' i.e. relative to the perfect
reflective diffuser (does reflective diffusion apply here)? Or, are the
measurements automatically normalized in hardware to the white point of the
monitor? Also is it possible to yield absolute colorimetry if we do not have
access to absolute luminance (foot-lambert or candelas or lux)?
Finally, what are colorimeters calibrated to? I hear the Spyder is
calibrated to D65 internally. What about a device like the X-Rite DTP92 (Ray
Cheydleur?)?
One last one, are there "standards" like GCA T-Ref or Lab-Ref that could
help validate the measurements of a colorimeter? I guess not, for practical
reasons, but let me ask anyway.
Let me know if this requires a separate thread.
Phil Green wrote:
>
Because CRT colorimetry is based on trichromacy (3 primary stimuli
>
mixing to produce the full range of colour sensations), the broadband
>
sampling of a colorimeter does a better job of providing the information
>
required to compute the CIE tristimulus values.
Roger Breton
Quibec Institute of Graphic Communications