"Measuring Conditions" - What Variables Affect the Results

Q - What is meant by “measuring conditions” or “measuring parameters”?
 
A - “Measuring conditions” include all parameters that might have affect on the resulting data.  These include but are not limited to such things as:

- Measurement geometry of the spectrophotometer ( 0/45, 45/0, diffuse D8, etc. )
- Physical filters  ( None, Polarization, UV, etc. )
- Aperture size
- Observer angle  ( either 2° or 10° )
- Illuminant  ( C, D50, d65, F2, F11, etc )
- Sample backing ( if sample is not completely opaque )
- Sample thickness ( if sample is transparent or translucent )
- Sample Gloss
- Temperature
- Humidity
- Curvature
- Color space calculations  ( L*a*b* or L*C*h° )
- Color difference calculations  ( dE, dECMC, dE2000 )
- Secondary illuminant if measuring metamerism

All these parameters above must be the same during your comparisons, recipe formulation etc.