How To Use The Nik Collection 6 Control Line

In May 2023, DxO released the Nik Collection 6 with several new features, including some to make selective adjustments easier. One of these was the Diffusion slider which you can read about in my Control Points article. Another was a new Control Line selection tool which appears to have been inherited from DxO PhotoLab. In this article we look at how Control Lines work and how to use them to improve your selective editing.

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What Are Control Lines

Control Lines are a DxO creation, first introduced in the PhotoLab 5 software. They allow you to select an area of an image and then apply specific adjustments to only that area. What makes this special is that it’s based on U-Point Technology which allows you to easily target the selection using colour and tone. It’s probably easiest to understand with a simple example.

Below you can see two screenshots of a photo being edited using Nik Viveza.

In image 1, we see the preview of the photo with the Control Line added. You can see the top and bottom of the Control Line indicated by the two red arrows. Then in image 2, we see the mask view of the photo. The mask view is a black and white representation of what’s being selected by the Control Line. The areas in black aren’t selected whilst the areas in white are. It’s these white areas that are affected by any adjustments we then apply.

How To Add Control Lines in the Nik Collection

Before we start, it’s worth highlighting that not all applications in the Nik Collection allow you to apply selective adjustments. You therefore won’t find Control Points or the new Control Lines in these applications.

Additionally, you might find that only certain filters in an application support Control Points and Control Lines. Nik Analog Efex is a good example of this. You will find both Control Points and Control Lines are available in the “Basic Adjustment” and “Light Leaks” panels but not others. For our example, we will use Nik Viveza 6 as this is one of the easiest for understanding using Control Lines.

To add a new Control Line to the image you are editing, go to the Selective Adjustments section of Viveza. You will find this in the panel on the right side of the interface.

To add a new Control Line, click the Control Line icon at the top left of this section. You will see two icons here. The one on the left is to add a Control Point whilst the one on the right is to add a Control Line.

After clicking the icon, position your mouse pointer over the image. You can then click, and whilst holding down the mouse button, drag downward. As you do this, you will see two dotted lines appear which mark the edges of the Control Line. When it’s the desired size, release the mouse button to complete it. You can see an example in the screenshot below.

The bottom line of the Control Line marks the edge of the selection area. Then there is a feathered or graduated selection between the bottom and top lines. Finally, everything above the top line is fully selected.

Had you clicked and dragged up with the mouse when adding the Control Line, the selected area would be at the bottom of the image.

After adding a Control Line to the image, it appears in the Selective Adjustments list. Each Control Line and Control Point you add has an automatically generated name. You can change this to something more meaningful by double clicking it.

To the right of the Control Line in the list is an icon displaying a white square with a dark circle in the centre. You can see this numbered ‘2’ if you look back to the Selective Adjustments screenshot. Click this to toggle the Control Line’s mask view on and off.

Controlling the Selection With the Sample Point

After adding a Control Line, we can refine what’s being selected. Although we said that everything above the Control Line is selected, that’s not entirely accurate. Each Control Line also has a movable sample point. This is represented by the eyedropper icon which you can see indicated in the screenshot above.

To reposition the sample point, click and drag the eyedropper icon using your mouse. If you check the screenshot above, you can see that the sample point is placed on an area of blue sky. This causes the Control Line to only select blue of the sky and to ignore the orange. You can see this in the screenshot below showing the mask view.

If you compare this screenshot to the one showing the image, you can see that the blue sky is being selected. But notice that the clouds on the left of the screen are also selected by the Control Line. That’s because they have an element of blue in them and are similar in tone (brightness) to the clear blue sky.

But what if we want our adjustments to affect only the clear blue sky and not the clouds? That’s when we need to use the Luminance and Chrominance sliders.

Refining Selections With The Luminance and Chrominance Sliders

Each Control Line you add to an image has a Luminance and Chrominance slider. You can use these to adjust the Control Line’s sensitivity to colour (Chrominance) and tone (Luminance). The following screenshot shows the two sliders being used.

When you move one of these sliders to the right, it means that pixels need to be a close match to the sample point to be selected. In the screenshot above, you can see that both Luminance and Chrominance sliders have been moved from their default 50% setting to 64%. This increases the accuracy of both the colour and tone selection. Now to be included in the selection, a pixel must be a closer match to the sample point placed on the blue sky. You can see the effect this has in the screenshot below.

Now the Control Point is selecting only the areas of genuinely blue sky and is ignoring the dark clouds on the left.

This article has introduced the Nik Collection Control Lines and using them to make selections. For a greater understanding of making selections with the Nik Collection, read my Control Point selections article.

More Nik Tutorials

You’ll find more high quality, free tutorials on my Nik Collection Tutorials page.