Originally Posted by catmother
No apologies necessary, Your posts are honest and informative.
I have several beefs (none with you).
The first deals with nomenclature, brightness, intensity, stimulus, lightness, are used to refer to a photometric quantity defined as Luminance.
I would prefer posters to use the official definition to avoid confusion.
And keep in mind that Lightness is Luminance weighted by human perception (Huffman, Poynton)
Second, too many posters refer to Luminance when they mean saturation and vice versa. I even have a post by Tom where I an not able to decide if he is referring to Luminance or saturation. Stimulus is very ambiguous.
Third, many respected calibrators fail to specify he luminance and saturation level they used.
Even Tom in his calibration of the Epson 5010 fails to do so.
Why is that important...
The AVS calibration thread is replete with posts pointing out that many FP in general and Epsons in particular do not calibrate well at 100% saturation.
One of the most germane posts is here:
Calibrating at 100% sat causes notable under saturation at 75, 50 and 25% resulting in a flat washed out image.
This can be avoided by calibrating at 75% saturation.
This was of only academic interest to me until the recent acquisition of an Epson 3010 full 3D FP
The 3010 like the 5010 Tom calibrated are new models, do these still need the 75% saturation method, would be nice to know. if Tom would clarify.
While the 75% sat method can cause over saturated green especially is the display has a wide gamut setting, the amount of 100% green in real word material is not likely to exceed 10-20% and would hardly be noticed by the viewer.