---
title: "Nonclamped Color Attenuation"
url: "https://help.maxon.net/c4d/en-us/Content/html/GLOW-GW_NC_GROUP.html"
section_path: "Advanced Render > Glow > Nonclamped Color Attenuation"
element_id: "GLOW"
group_id: "GW_NC_GROUP"
description: "Using the parameters on this page, you can restrict the glow to rendered pixels that are within a defined brightness range. Set this range by entering …"
---

## Nonclamped Color Attenuation

### Use

Parameter ID: `GW_NC_USE`

Using the parameters on this page, you can restrict the glow to rendered pixels that are within a defined brightness range. Set this range by entering values into the boxes for Min Intensity and Max Intensity, where 100% represents bright white (RGB 255/255/255). Enter values above 100% if you want restrict the glow to non-clamped colors (i.e. colors above RGB 255/255/255). Even though non-clamped colors are no brighter on screen than pure white, this helps you to create a sense of intense light in these special picture areas.

### Min. Intensity

Parameter ID: `GW_NC_MIN` · Range: [0..+∞%]

### Max. Intensity

Parameter ID: `GW_NC_MAX` · Range: [0..+∞%]

These values define a brightness range. Each rendered pixel that falls within this range will generate glow. You can restrict the glow to non-clamped colors (see paragraph above) by setting Min Intensity and Max Intensity to values greater than 100%.

### Use Key Color

Parameter ID: `GW_NC_COLON`

### Key Color

Parameter ID: `GW_NC_COL`

### Color Variation

Parameter ID: `GW_NC_COLVAR` · Range: [0..100%]

![Image: 004130.jpg](https://help.maxon.net/c4d/en-us/Content/Resources/Images/004130.jpg)\
Glow restricted to a key color.

You can restrict the glow to a particular color. Use the color box to choose this **key color**. Since most rendered surfaces are gradations of color rather than a single tone, you can also specify a tolerance value for the key color, which you enter into the Color Variation box. If you set Color Variation to a value that is too low, such as 0%, you may find that only a few pixels will glow.

### Use

Parameter ID: `GW_NC_SIZEON`

### Size

Parameter ID: `GW_NC_GSIZE`

### Use

Parameter ID: `GW_NC_DENSON`

### Density

Parameter ID: `GW_NC_GDENS`

### Use

Parameter ID: `GW_NC_LUMON`

### Luminosity

Parameter ID: `GW_NC_GLUM`

### Use

Parameter ID: `GW_NC_GCOL`

### Color

Parameter ID: `GW_NC_GRAD`

You can use gradients to refine the following properties from the Glow page: Size, Density, Luminosity and Color (see **Glow** entry).

![Image: 004131.jpg](https://help.maxon.net/c4d/en-us/Content/Resources/Images/004131.jpg)

Think of these gradients as running from the **Min** value to the **Max** value (or within the color variation). In the gradient, black represents a value of 0, white represents the value defined on the **Glow** page.