Many of Apple's latest iPhones, including the iPhone 7 Plus, iPhone 8 Plus, iPhone X, iPhone XS, iPhone XS Max and iPhone XR, support a camera mode called "Portrait." You've probably heard people talk about it: it's what lets you use your iPhone to take fancy professional-looking pictures with in-focus subjects and blurred backgrounds (otherwise known as "bokeh.") Portrait Mode is really easy to use, and I'll walk you through how to use it. If you have one of Apple's iPhones that launched this year, you can adjust the amount of background blur in a portrait picture, so I'll show you how to do that, too.

How to use Portrait mode on the iPhone

First, launch your camera app and then choose a subject. On most iPhones, this can be anything, from a person, to an animal or just a simple houseplant. On the iPhone XR, howeverr, Portrait mode works only for people.

Next, hold your finger down on the area of the camera app that says "Photo" in yellow, and slide your finger so that the mode switches to "Portrait."

Now, aim your camera at the subject that you want to take a picture of. When Portrait Mode is ready to work, you'll see an area at the bottom of the screen that highlights and says "Natural Light." That means you're good to take a picture. Your picture should look something like this, with the object in focus while the background has a nice bokeh effect:

This is a regular default Portrait picture from the iPhone. Sara Salinas | CNBC

Here's what that same scene looks like without Portrait Mode on:

This is a regular picture without Portrait Mode activated at all. Sara Salinas | CNBC

Not as fancy, right? It also includes more of the background, since it's not focused on the subject and doesn't use the telephoto zoom lens for the picture.

How to apply Lighting effects to portrait pictures

I applied black and white stage lighting to this Portrait Mode picture. Sara Salinas | CNBC

Apple has Lighting effects that you can apply to Portrait pictures, too. You can create some really fun shots, including a black and white "Stage Lighting" picture like the one above. Here's how: Open a Portait Mode picture you've snapped.

Tap on the cube icon to the right of the picture and slide your hand.

You'll see your picture change as different lighting effects are applied.

Choose the one you like and tap "Done."

How to adjust the blur in Portrait mode on your iPhone

If you have one of Apple's newer iPhones, including the iPhone XS, iPhone XS Max or iPhone XR, you can adjust the amount of blur, or bokeh, in the background of a Portrait photo. To do that: Open a picture you snapped in Portrait Mode.

Tap Edit.

Swipe along the dial on the right of the screen. You'll see the background blur change in real time. In this case, I've taken one of the portrait photos from above and increased the blur, adding more focus on me, the subject. So we've gone from this:

This is a regular default Portrait picture from the iPhone. Sara Salinas | CNBC

To this:

In this picture, I've increased the background blur to focus on me. Sara Salinas | CNBC

Or you can remove the blur almost entirely and go to this:

In this picture, I've decreased the blur of the Portrait Mode shot, adding some clarity to the background. Sara Salinas | CNBC