# Spectral viewer

## 1. How to use Spectral Viewer

In a first time, we need to load or capture light samples, or color samples, to display their curves.

Capture them:

{% content-ref url="../colors/capture-a-light" %}
[capture-a-light](https://docs.coraye.com/colors/capture-a-light)
{% endcontent-ref %}

{% content-ref url="../colors/capture-a-color" %}
[capture-a-color](https://docs.coraye.com/colors/capture-a-color)
{% endcontent-ref %}

Or load a .sp (light sample) or .spc (color sample) file:

![](https://817532847-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LjCNvq-KDdSRn96lZIz%2F-MEwuswOW7LnH7no5Z9q%2F-MExT6E6UrW7XZ8EyPHA%2FOpen%20file.png?alt=media\&token=71e9f4f1-97e1-497d-b8ae-4dec5a34eae8)

![](https://817532847-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LjCNvq-KDdSRn96lZIz%2F-MF-s19TE1B9L0y_5ZhP%2F-MF-ttDguu3GDdmpaC5M%2FSpectral%20Viewer.png?alt=media\&token=c97ff6ac-aca9-47d0-8d9b-0725c1134420)

Samples will be added in the left column.\
Into the main window of Coraye, click on the **Spectral Viewer** pictogram (the second icon on the top middle).

![](https://817532847-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LjCNvq-KDdSRn96lZIz%2F-MF-s19TE1B9L0y_5ZhP%2F-MF-uDQIad68_fKNmluz%2FCapture%20d%E2%80%99e%CC%81cran%202020-08-18%20a%CC%80%2011.30.41.png?alt=media\&token=38150b1b-2815-4d8b-b242-d8af76f2d01f)

Then click on the small square at the right of the sample name.\
The spectral curve will be displayed 

Example: Fluo tube light.

![](https://817532847-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LjCNvq-KDdSRn96lZIz%2F-MF-s19TE1B9L0y_5ZhP%2F-MF-udBzmSrkFgLwB9Z1%2FSpectral%20Viewer%201.png?alt=media\&token=99f952df-dd59-40bb-8f6b-9071178cb494)

Example: Natural day light

![](https://817532847-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LjCNvq-KDdSRn96lZIz%2F-MF-s19TE1B9L0y_5ZhP%2F-MF-uy8vHGX2cgKXKEPq%2FSpectral%20Viewer%202.png?alt=media\&token=4dd3288f-1c25-4913-8a35-8797305fa673)

Spectral Viewer is also able to display reflectance curves for color samples.\
The color of the curve is the color corresponding to the color sample.

![](https://817532847-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LjCNvq-KDdSRn96lZIz%2F-Lmsx5UyVui5aXN9BRAP%2F-LmtK7ZRQ5q77T4VonVf%2FSpectral%20Viewer%206.png?alt=media\&token=a4519450-6ab7-435e-8578-170bbc2a0857)

### 2. Customize yours curves

![](https://817532847-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LjCNvq-KDdSRn96lZIz%2F-MF-s19TE1B9L0y_5ZhP%2F-MF-yZRV_C_yXfzGE20h%2FSpectral%20Viewer%204.png?alt=media\&token=1d883909-ff74-4dd2-9abf-c262dd76e7ed)

### **3. Metamerism**

By comparing the reflectance curve of a measured color sample with the spectral curve of an illuminant, we can get an idea of what will be the influence of an illuminant on a colored sample. (Metamerism)\
You can also use the slider on the **scale** to compare the curves between them.

![](https://817532847-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LjCNvq-KDdSRn96lZIz%2F-MF-s19TE1B9L0y_5ZhP%2F-MF-z0EKzzuxAN76a0My%2FSpectral%20Viewer%205.png?alt=media\&token=5f06bbed-823e-494a-b62f-f5167e882c52)

{% hint style="info" %}
In colorimetry, **metamerism** is a perceived matching of colors with different (nonmatching) spectral power distributions. Colors that match this way are called **metamers**.
{% endhint %}

When you hover over the curves you get the values in mW / (m2.nm)

![](https://817532847-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LjCNvq-KDdSRn96lZIz%2F-MF-s19TE1B9L0y_5ZhP%2F-MF-zehtoMxi_dsUeNjU%2FSpectral%20Viewer%206.png?alt=media\&token=f1661007-7ed2-4e36-8132-f2d3975c5cf2)