I have been having some fun with Nikon Capture NX lately. It is not Photoshop, but it has some really nice features that can make the same photo enhancements effortlessly with out purchasing the much more expensive alternative. Today, I will present a tutorial on how to remove distracting background using the selection brush in Capture NX.

The selection brush tool allows you to selectively apply effects and enhancements. You can do the same in Photoshop using layers and layer masks, but the selection brush tool in Capture NX is more intuitive and doesn’t require users to master the concept of layers and layer masks.

The selection brush tool is highlighted with a red circle in the screen capture shown above. Next to the brush icon, you can see a small “+” button and a small “-” button. These are the two modes the selection brush can work in. In the plus “+” mode, the brush will allow you to paint in the effect you have previously applied to the entire image. In the minus “-” mode, the brush will allow you to remove the previously applied effect from where you paint over with the brush. Confused a little bit? Don’t worry. It is actually much easier than it sounds.

Let’s get started

The original photo with busy background

I took this photo at a local street fair a few months ago. The crystal ball looked really fascinating so I took a few pictures of it. Later I felt that the background looks very distracting. So, what can be done to make the crystal ball stand out? Three possible ways:

1. Blur the background as if the photo were taken with a very large aperture
2. De-saturate the colors of the background
3. The combination of the above

I am going to show you how to do #1 first. The other two methods are just simple extension of the same selection brush technique.

Apply the Gaussian blur effect

We start by blurring the background. The command is “Adjust->Focus->Gaussian Blur…” as shown in the following illustration.

The Gaussian blur options box will appear with two option sliders, (1) Radius, and (2) Opacity. The radius slider controls how far the software will try to smear out the details. This is dependent on how much blurring you want and the file size. The Opacity slider controls how strongly the effect will be applied to the image. For this particular example, I leave both sliders at highest setting (100px and 100%).

You will see something like the following in the main edit window:

Selection brush modes

Now you have two ways of using the selection brush: use the “+” mode or use the “-” mode. As the symbols imply, the “+” mode is an additive mode while the “-” mode is a subtractive mode.

If you select the “+” mode by clicking on the “+” button next the brush icon, the blur effect will disappear completely because Capture NX expects you to paint in the blur effect where you want them. In this case, the background. So you will need to start painting on the background.

If you select the “-” mode, nothing will happen to the blur effect you already applied to the whole image at beginning. When you start to paint in the subtractive mode, the blur effect will be removed from where you paint. Since we want to have the crystal ball look shinny and crisp, we will need to paint over the crystal ball.

You can use either mode and you can achieve the same end effect. For this tutorial, I used “+” mode to paint over the background area.

Selection brush operation

When painting with the selection brush, you can decrease or increase the size of the brush using “[" and "]” keys on your keyboard. With the selection brush active, you can also right click anywhere on the image to reveal the selection brush options dialog box as following.

Alternatively, you can also double-click on the brush icon in the toolbar to access the selection brush options. Adjust the options as needed.

If you accidentally paint into the crystal ball area, you can simply switch to the “-” mode and paint it right back. Or, you can undo it by “Ctrl-z”.

You can go to “View->Show Selection” to view the selected area (appear to be white in the following example). Unselected (unpainted) areas appear red. I found this mode useful when trying to make sure no spots are left out unselected where they should.

The result

The result is shown in the image below. The distracting background is now a silky creamy blur. I guess I might have overdone it a little bit by also blurring out the details on the table. Well, this is just for illustration, so you can do whatever you feel like on your own photos.

Background blur using Capture NX

Other options

As mentioned earlier, another way of removing the background distraction is to make it de-saturated (black and white). This is done in the similar approach, just use the black&white photo effect (Filter->Photo effects, select Black and White in the method dropdown box) instead of Gaussian blur in the editing step prior to the selection brush. The result is the following photo.

Background BW effect using Capture NX

The other way to remove the background distraction is to apply both Gaussian blur and black&white effects to the background. You could do it in two separate editing steps with two separate selection brush painting operations. Obviously this is very tedious.

Here is the trick you will like: Insert both effects in the same editing step before using the selection brush. By default, Capture NX puts two effects in two separate steps in the Edit List and the selection brush only works on the last or the edit step you select in the Edit List. However if you hold on the shift key when adding a new effect, Capture NX will put it in the same edit step as shown in the example below.

The added benefit of this approach is that you can easily turn on or off the individual effects in a nondestructive manner, by using the circular checkbox next to the effect. Actually that was how the three different variations of the example photo were created. The following is the result with both Gaussian blur and the BW photo effect.

Background blur + BW effect using Capture NX

The final words

I hope you enjoy reading this tutorial on Capture NX selection brush. If you have any questions or suggestions, please feel free to use the comment box below. Thank you.