Colin smith change focus feature image

How to magically change the focus of photos in Photoshop with Colin Smith

August 23, 2023

Maybe you’ve been using Adobe Photoshop for a while, or maybe you’re just getting started. There are many ways to do different things with the software, as well as all kinds of tips, tricks, and hacks to do things simply and easily.

In this tutorial Colin Smith, the creator of PhotoshopCAFE, shows you a powerful way to change the depth of field and blur the background of a photo in Adobe Photoshop. Check out the video below for the Adobe Photoshop and Lightroom tutorial, click here to visit PhotoshopCAFE and download the project files if you’d like to try the technique for yourself, and read on for all of the details.

Depth blur

Alright, let’s get started with this train. So the first thing we’re going to do is go to Filter in the menu bar, choose Neural Filters, then turn on Depth Blur. Maybe you’ve seen this filter before, but I’m going to show you how to manually overwrite things and get a much better result than just using than your filter on its own.


If you wanted to change the area of focus, you could simply just click on different parts of the photo and notice how this will recompose it. But you may see how there’s areas that get missed. Let’s look at how to fix all of that and actually use a better way of applying it than depth blur.

Depth map

So we’re going to go all the way to the bottom of the menu and choose output depth map only. On this depth map, lighter-colored things means they’re further away. Where they’re darker means they are closer to the camera.


Okay, let’s start with the first trick that you might not have seen before. Increase the effect of the depth map by using Levels (Ctrl/Cmd+L). And then what we’re going to do is take the shadow area and slide that closer to the middle. And it’s also going to the midtone. So what we’re doing and we’re intensifying those grays to give us more of an effect.

The next thing we need to do is to look at the area between the sticks to the right of the train. We want to make sure that this area is on the same depth plane as the background. Right now, they are different shades of gray so they will be on a different plane. So let’s make a selection around these areas.


Object selection

Select the Object Selection Tool (W) and select the area between the sticks. Then use the Polygonal Lasso Tool (W) and add to the selection. The way to do that is to hold down the Shift key and just click the points of the rest of the area.

Applying the blur

Turn back on the depth field top layer. Notice these are the shades that we want to be painting with. So grab a brush, hold down the Alt or the Option key and that will make a sample. Make the brush a little larger and let’s paint those out. Just pick up the same kind of tones.


All right, let’s go to the channels. And what we want to do now is duplicate one of those channels. Let’s just grab any of them red, green or blue, they’re all the same. Duplicate it with Cmd/Ctrl+J. And then this gives us another map. We’ll just call it “MAP.” It doesn’t really matter what you name it. Make sure you select RGB again. Let’s just duplicate the background so we can show it before and after.

Now let’s use a really powerful tool to apply the blur. We’re going to choose Filter > Blur > Lens Blur. This actually simulates the lens on a camera. So as you can see, you can choose different types of apertures. Now the important thing is we want to make sure under “Source” we’re choosing our depth map.


Let’s increase the blur so we can see the radius. Now watch what happens if we click the “Set Focal Point.” If we click on the front of the train, notice how now it comes in nice and sharp. Or we could click the back of the train. We could click on different parts of the photo to bring these areas into focus and notice we get the proper background blur in these areas there because of the way we selected them. Click Okay. Now we can look at it before and after.


So as you can see, these automatically generated depth maps are incredibly powerful. Let me know your thoughts if you learned anything new in this video, and if you’re new welcome to Photoshop, hit subscribe turn on notifications so you won’t miss any of my videos. And if you got any value out of this video, smash that Like button into dust and until next time.

Related posts:

Ana Carolina on 3D sculpting, her creative journey, and her upcoming session at ZBrush Summit 2023

Ana Carolina on 3D sculpting, her creative journey, and her upcoming session at ZBrush Summit 2023

The top five online learning resources for aspiring artists

The top five online learning resources for aspiring artists

Teaching, learning, and visual thinking with Bamboo Paper

Teaching, learning, and visual thinking with Bamboo Paper

The complete guide to Adobe Photoshop brushes, Part 1: The toolbar

The complete guide to Adobe Photoshop brushes, Part 1: The toolbar

Connect with Wacom on social media

Takeover Alert!⁣
#ZBrushSummit 2023 starts this week and @WacomEdu has a treat for you 🍬⁣
Join @gnomon_school social media manager Chris Hawley for an Instagram takeover at @WacomEdu On September 28th & 29th! Tune in as Chris highlights the annual ZBrush Sculpt Off, interviews Gnomon faculty, attends workshops featuring 3D industry leaders, and more!⁣
#Wacom #WacomForEducation #Education #Gnomon #ZBrush #VFX #Animation @maxonzbrush⁣
82 0
Otherworldly floral beauty by artist @ali.hassan.arafatt created as cover art for musical group @separat.a. 🌺🍃⁣
The detailing on the hair and flora have left us in awe looking at this fantastical piece! 🖌️😍⁣
#MadewithWacom #digitlart #art #illustration
339 7
Creativity happens when less expected 💡
In @fragileart’s case, in math class 😅😂

Tell us, when did you discover that you wanted to become an artist?

#MadewithWacom #Wacomartists #WacomCintiq
1071 5
Why choosing when you can try it all 😉

With no need for batteries, use a pen that feels and looks just right in your hand.

Find the right pen option for you and see where it takes you! ✍️ Link in bio!

#WacomAdventureProgram #WacomOne #CreativeJourney
853 15
osu! player and content creator KoiFishu shows you the new Wacom One M pen tablet in action! 💯⭕✍️⁣
#gaming #osu #osugame #rhythmgame #wacom
6329 41
✨ This is your sign to get your first Wacom One and unlock all the possibilities ✨

Your journey begins here, see where it takes you! ✏️ Link in bio!

#WacomAdventureProgram #WacomOne #CreativeJourney
585 7
Adorable Bocchi the Rock! #fanart by @tonicaballeroart that charmingly captures the fun nature of the Kessoku band members. 🎤🎸🥁⁣
 ✨ Who's your favorite character?⁣
#MadewithWacom #FanartFriday #BocchitheRock #anime #art #digitalart
1236 2
Artist @samrodriguezart uses beautiful colors, abstract ideas, all paired with his realistic portrait work to create dreamy works of art. 🎨🌹🔴⁣
We would like to welcome Sam to the Wacom community as he recently made the switch to a Wacom Cintiq Pro! ✍️🥳🎉⁣
#MadewithWacom #illustration #abstract #art #digitalart
338 3
That feeling when you open a new and fresh Wacom One 🤩🤩🤩

Unbox yours and show us! Link in bio!

#WacomAdventureProgram #WacomOne #CreativeJourney
789 13
Clean #WacomWorkspace of illustrator @laurasuarez. 🌱 The light wood accents, plants, and airy space would inspire anyone! 💡✍️⁣
#Wacom #Cintiq #deskgoals #wfh #desksetup
462 7
Wondering how to change your Wacom pen’s nib? Here’s a step-by-step tutorial 🖊️✨

PS: Stay curious, keep learning, and let’s see where your Wacom takes you! 👉🏻 Link in bio

#WacomAdventureProgram #WacomOne #CreativeJourney
986 35
Here's a magical start to your Monday! 🪄🐉🦜⁣
Concept artist shares his series of combining unlikely pairs of creatures to create fantastical beasts! ✨✍️ ⁣
What animals or creatures would you pair together? 👀⁣
#MadewithWacom #WacomCintiq #fantasy #art #digitalart #dragons
9343 47