Control of an illuminant
Illum Reader is a function that analyzes light.
Its purpose is to check the quality of your light in a light booth or under your viewing conditions.
This feature can only work with the following spectrophotometers:
- Konica Minolta MYIRO (Optional Ambient Light Adapter)
- XRite Eye One Pro
- XRite Eye One Pro (EFI ES 1000)
- XRite Eye One Pro 2 (EFI ES 2000)
- XRite Eye One Pro 3 (EFI ES 3000) and XRite Eye One Pro3 PLUS
Attention some XRite I1 Pro OEM cannot measure the illuminant
How to use Illum Reader
Click on the icon "Create Light" in the toolbar of Coraye
Make sure your spectrophotometer is connected.
When the "Read the test pattern" window appears, click on "I'm ready".
A new window will appear to calibrate your spectrophotometer.
Place the spectrophotometer in its calibration position in its calibration position.
Then click on the Start calibration button.
When the calibration is complete, a new window will appear.
Attention, you must use the cap to read the light with
the Konica Minolta MYIRO, the XRite Eye One Pro 1, 2, 3 and 3 PLUS.
To capture the light, it is now sufficient to measure directly with the spectrophotometer.
Successive measurements will be displayed one below the other.
You can take multiple measurements and rename them as you want.
When your measurements are complete, click on “ Save and exit”.
Your light samples will be added in the left column.
How to manage your light samples
Right click on the color to rename, duplicate and delete.
These .sp files are useful for sharing and saving your light samples.
What are the values associated with the measured sample?
When we measure a light, we can get information like CCT, CRI, Ra, Brightness, Lab and x, y.
The CIE Color Rendering Index ( CRI ) is a method of determining how the illumination of a light source in eight samples compares to that provided by a reference source. Cited together, the CRI and CCT provide a numerical estimate of the reference (ideal) light source that most closely approximates a given artificial light and the difference.
The IRC is a quality index for evaluating an illuminant. It is expressed as a percentage. the higher the value, the better the quality of the illuminant.
The color temperature of a light source is the temperature of an ideal blackbody radiator emitting light of a color comparable to that of the light source.
Color temperature is a characteristic of visible light that has important applications in the fields of lighting, photography, videography, publishing, manufacturing, astrophysics, horticulture and other fields.
In practice, the color temperature only makes sense for light sources which in fact correspond quite closely to the radiation of certain black bodies, that is to say a light ranging from red to orange to yellow to white. to bluish white; it does not make sense to speak of color temperature, for example, of a green or purple light.
Color temperature is usually expressed in kelvins, using the symbol K, the unit of measurement for absolute temperature.
The color temperatures greater than 5000 K are called "cold color" (bluish), while the lower color temperatures (2700-3000 K) are called "warm colors" (yellow).
"Warm" in this context is an analogy to the heat flux radiated from traditional incandescent lighting rather than temperature.
The spectral peak of warm-colored light is closer to infrared, and most warm-colored natural light sources emit significant infrared radiation.
The fact that "warm" lighting in this sense actually has a "cooler" color temperature is often confusing.
To save your measurement, right click on the measured light in the left bar, then select "Export" to save as a .sp file.
As you see, you can also rename, duplicate or delete the file when you click on it.
Control your stand or your viewing conditions
IllumReader can be useful for checking uniformity, color temperature, light intensity in a booth, and checking viewing conditions for proofs, objects and prints. In the field of graphic arts, ISO standards have been defined to standardize the conditions for viewing prints. Knowing how to control your light is, in a way, knowing how to control your color.
ISO 3664: 2009 - VIEWING CONDITIONS
• The relative spectral power distribution should match that of the CIE D50 illuminant.
• UV energy must comply with CIE D50 illuminant (correlated with M1 in ISO 13655).
Two levels of light intensity
• Critical comparison P1: for example two impressions: illuminance 2000 ± 500 Lux
• Practical evaluation of P2: less critical comparisons, for example. software-proof hard copy: 500 ± 125 Lux or exact adjustment of the illumination of the lighting booth to be monitored
• Homogeneity (control over 9 areas in your stand)
• Surrounding: neutral gray diffuse surface
• Viewing angle to avoid reflections
Light measurement can be used to calculate an Isc profile.
View your reflectance curves in Spectral Viewer.
It might be helpful to compare the reflectance curves of your color sample with a spectral curve of a specific light to understand the effect of metamery.
If you need to view the spectral curve of your measured light, you can use the spectral viewer.
For more information, see chapter: Spectral Viewer