Blogs
Sources for BRDF and BSDF Equipment and Testing Services
Posted on by Ken Phillips
In industrial colorimetry of QA non-luminous materials, assumptions are made that light reflected from or transmitted through a surface is relatively uniform, with only diffuse and specular components. To promote inter-instrument agreement, the CIE geometries for collecting the reflected or transmitted signal of non-luminous materials are standardized into directional and diffuse sphere types. BRDF measurement serves as more of a […]
How is polarization minimized in HunterLab sphere instruments?
Posted on by Ken Phillips
FAQ: “Do you sell a depolarizer for my HunterLab sphere instrument? On occasion we test polarized samples and there is definitely a dependence on the orientation of the lens. I was wondering if adding a depolarizer would eliminate this phenomenon?” Ken PhillipsMr. Philips has spent the last 30 years in product development and management, technical […]
Directional Instruments
Posted on by Ken Phillips
HunterLab manufactures bench top instruments with two different geometry types: directional 45/0 (or 0/45) and diffuse sphere instruments, as discussed in a previous blog note. A 45/0 directional instrument illuminates the sample at a 45˚ angle from the sample surface and the detector is located 0˚ in line perpendicular to the sample surface. The […]
Measuring Visual Differences with dE CMC
Posted on by Ken Phillips
Can you see a visual difference between the three samples above? Chances are if you can see a difference between samples then HunterLab instruments can measure and quantify these variances. There are several ways to quantify differences with color measurement. You can evaluate dL* da* and db* values to see how samples vary from a […]
Metamerism Index
Posted on by Ken Phillips
Why do the samples above look the same under one lighting condition but different under another? These samples exhibit metamerism, which means they match under some lighting conditions but not others. Ken PhillipsMr. Philips has spent the last 30 years in product development and management, technical sales, marketing, and business development in several industries. Today, […]
Measuring the Color of Olive Oil
Posted on by Ken Phillips
Olive oil is produced by grinding whole olives and extracting the oil by mechanical or chemical means. Olive oil has a wide variety of applications cosmetics, pharmaceuticals, soaps, but most commonly is used in cooking. Can HunterLab instruments accurately determine the quality of olive oils quantitatively? Ken PhillipsMr. Philips has spent the last 30 years […]
Human Observers
Posted on by Ken Phillips
This is the final blog note article in our series describing the Visual Observing Situation Model in which we will discuss human observers. Previously we discussed how the illuminants and objects are quantified to help measure color. In the human eye there are rods that are responsible for low light vision and cones that are […]
Objects
Posted on by Ken Phillips
In this series of blog notes we have discussed what is needed to quantify color and how light sources are quantified. The second element of the visual observing model that must be quantified is the object that modifies the white light source. Ken PhillipsMr. Philips has spent the last 30 years in product development and […]
Light Sources and Illuminants
Posted on by Ken Phillips
The previous blog note discussed the three elements required to see color; a white light source, an object, and a human observer. In order for HunterLab instruments to measure color we need to be able to quantify, or assign numbers, to these three elements. Ken PhillipsMr. Philips has spent the last 30 years in product […]
How do you quantify color?
Posted on by Ken Phillips
HunterLab instruments measure the color as it relates to the quality of the product. To be able to begin to measure and quantify color we have to know more about why colors appear as they do. As humans we all see and perceive color differently; this is because the human perception of color is a […]
What is a visual limit for Haze%?
Posted on by Ken Phillips
FAQ: “What is a visual limit for Haze%? When should I be able to see a difference in a sample?” A perfect clear of 0% would be air for transparent solids and the transmission cell of a defined path length filled with DI water for transparent liquids. It should also be noted that the Haze% […]