# Haze

Haze refers to the scattering of light by a surface that causes a reduction in the contrast of a reflected image. It results in a milky appearance which can reducing the perceived depth of the finish.

![Reflection Haze Examples](reflection-haze-examples.png)

The visibility of haze on a surface is influenced by viewing conditions and the background colour of the material.

Viewing conditions-  Haze effects are highly visible when viewed with a high intensity specular light- for example viewed with a powerful inspection light or outside in bright sunshine.

Haze effects diminish the perceived quality of high gloss coatings and are usually an undesirable attribute.

## Log Haze Compensated- LogH C (LogHU)
The LogH C parameter in the Rhopoint Aesthetix represents the logarithmic haze value calculated using contrast-based measurements.

LogH C (compensated) compensates for background colour when measuring Haze, hence this is value is used extensively in QA Application.

LogH C measurements with Aesthetix are correlated to values measured with Rhopoint IQ.

In the Rhopoint Aesthetix, this process is performed using a 60° measurement angle instead of the traditional 20°, with haze regions defined between 2° and 4° off-specular angle.

## Log Haze- LogH (LogH)
The LogH parameter in the Rhopoint Aesthetix is derived from the haze measurement process. It is calculated by converting the haze value into a logarithmic scale. The ASTM E430 and ISO 13803 standards describe haze evaluation based on the ratio of luminous flux in off-specular regions to the flux from a specular gloss reference sample. 
is the flux from the specular gloss reference sample.

In the Rhopoint Aesthetix, this process is performed using a 60° measurement angle instead of the traditional 20°, with haze regions defined between 2° and 4° off-specular angle.

Note- Log H value is no longer used in QC applications as the measured value is influenced by background colour of the paint. 

## Michelson Contrast Haze- MC H (HU)
The MC H parameter, or Michelson Contrast Haze, in the Rhopoint Aesthetix is a haze metric based on Michelson contrast. 

It quantifies the difference between the luminance of the specular highlight and the adjacent off-specular regions. This method provides insights into how surface microstructure affects visual haze, which traditional haze measurements may overlook.The MC H parameter, or Michelson Contrast Haze, in the Rhopoint Aesthetix is a haze metric based on Michelson contrast. It quantifies the difference between the luminance of the specular highlight and the adjacent off-specular regions. 

This method provides insights into how surface microstructure affects visual haze, which traditional haze measurements may overlook.