Guide To Focus Stacking In Lightroom
Sometimes a photograph benefits from having only the subject in focus against a blurred background, and sometimes the impact is better if everything is sharp.
But have you ever tried to keep everything in focus? This isn’t always as easy as it sounds.
If your foreground is very close to you and the background is far away, this is technically impossible unless you’re using tilt-shift lenses. Even with this special gear, it can be very difficult.
The same goes for macro and close-up photography.
So, how is it done? With a post-production technique called focus stacking.
What is Focus Stacking?
How much area of your picture is in focus is called the depth of field.
How wide or narrow this is will depend on a combination of three things: the aperture, the distance between the foreground and the background, and the focal distance of your lens (which also determines how close you are to your subject).
Including a foreground in photography (which is in focus as much as the background), is a great way to tell two stories at once, or simply show everything in a scene in full clarity to the viewer.
If you want to have your entire scene in focus but the depth of field is not enough, you can photograph it multiple times, placing the focus on different points.
Then, you ‘stack’ all these pictures and blend them together to get one photograph where everything is in focus. This is focus stacking.
As you can see, this is done in post-processing. However, to get your series of focus stacked images, you need to plan on using the technique from the start of the photo shoot.
This is because you need a certain number of photographs covering every point of focus as material to work with.
So, let’s start from the beginning and learn how to take the pictures you’re going to need for focus stacking.
How Do You Take Pictures for Focus Stacking?
The example above shows my shoe which was shot by stacking focus and using auto blend in Photoshop. Let’s have a closer look at how to produced a stacked focus image.
First of all, you’re going to need to shoot with a tripod. All your images are going to overlap and then blend, so the framing needs to be exactly the same.
Also, if you’re working with a macro lens, the difference in focus is so small that you need to be extremely precise, which can’t be done hand-held.
If it’s possible, especially for macro photography, always use the live view. This way you can zoom in and adjust the focus.
This means of course, that you have to use manual focus. Since we’re on the subject, everything else has to be done manually as well.
The ISO, shutter speed and aperture need to be set in manual mode to keep the exposure constant throughout the photoshoot. Also, if you’re using natural light try to do them as quickly as possible so the exposure doesn’t change in between shots.
Ok, now let’s talk settings. The priority needs to be on the aperture because we’re working with the depth of field.
As you know, a small aperture means a deeper depth of field, and a wide aperture results in a shallow depth of field.
Having said that, lenses have a sweet spot at some point in the middle of their aperture range. That’s to say that between f/8 and f/11 you’ll probably get the sharpest image that your lens can capture.
So, find your lens’ sweet spot and set it as your aperture. Then adjust the shutter speed and ISO according to the lighting conditions of your scene.
I recommend that second in the priority list be the ISO. Keep it as low as you can to avoid any noise. Then in third place, you can set the shutter speed which can be slow because you’re using a tripod.
If it’s too slow you can use a remote shutter or activate the timer mode so that you don’t cause any movement when you’re pressing the shutter.
Now that you have everything ready, it’s time to start shooting. Take your first photo with the focus set in the closest part of the scene.
Then, repeat the photo as many times as you need, adjusting the focus point by moving it slowly towards the furthest point until you cover the entire scene.
The more images you have, the more information there will be for you to work with. So don’t be afraid to take a lot of shots. Of course, sometimes three or four are enough, but it’s always better to be safe than sorry.
Some Nikon cameras have a ‘focus shift’ function especially for this kind of work. If you have one of these cameras, you can set the number of shots and the camera will automatically move the focus in each one.
Now, let’s jump into the computer to do the focus stacking.
How to Focus Stack in Adobe Photoshop Lightroom
The actual focus stacking takes place in Photoshop, but passing through Lightroom is a good idea if you need to make any adjustments that have to be done to the entire series, e.g. correcting exposure, noise reduction, lens correction, etc.
If you tried to do them one by one it would be time-consuming and difficult to get the same result in all of them, so let’s start the process in Lightroom Classic to edit and sync the photos in preparation for the focus stacking.
Step 1: Import Your Images Into Lightroom
Download the images you took into your computer and import them into Lightroom Classic using the Import button from the left.
Now you’ll have all your images showing as thumbnails. Choose one (it doesn’t matter which) and make any editing that is needed.
Step 2: Edit Your Image
Using the Develop window, you can make all the edits that your picture may need. You can adjust the white balance, the exposure, lens corrections, and any other adjustments you think are necessary.
Now, remember that all the images you’re going to stack need to look the same, so anything that you adjust to this file needs to be applied to all the others.
Step 3: Sync Your Edits
This is why using Lightroom Classic for your focus stacking process is useful. With only one click you can apply the same edits to all the images saving you the time and effort of doing it manually.
To do this, select all your files from the photoshoot and then click on the Auto Sync button from the bottom of the Develop panel.
Extra Tip: If you don’t have Lightroom, you can create a Photoshop Action to apply the edits on all your images and make the workflow more efficient.
Step 4: Open in Photoshop
Ok, now that your images are ready for the focus stacking you need to send them to Photoshop.
Because they need to be stacked in the same document, go to the Photo menu, then select Edit In and Open as Layers in Photoshop.
Alternatively, you can right-click on the selected files and then choose the Open as Layers in Photoshop command.
This process can take a few minutes.
Step 5: Auto-Align Layers
Using the Auto-Align Layers tool will correct any imperfections that could come if your camera wasn’t perfectly still from one photo to another when you took the pictures.
Also, it will compensate for the focus breathing. This is not something you can control, it’s just something that happens with most lenses. When you adjust the focus, the focal length changes too.
Step 6: Auto-Blend Layers
All your pictures are now ‘stacked’ one on top of the other, but you only see the one on top.
To merge them into one completely focused image you need to go to Edit, Auto-Blend Layers.
This will open a dialogue box. Choose the option called Stack Images. Enable the options Seamless Tones and Colors and Content-Aware Fill Transparent Areas, then click OK.
Depending on the quantity and quality of the files this process can take a little while, so just be patient.
Step 7: Fine-Tune Your Image
That’s it – by now you should have a fully in-focus image that was created as a separate layer merging all the others.
Sometimes the result isn’t perfect and you have to adjust some parts that have ‘ghostly’ edges. You can do this by using the layer masks that Photoshop created.
Or you may need to fix any spots or imperfections using the Clone tool or the Healing tool. This depends on each case.
After that, you can flatten the image if you want to make it lighter and you’re sure that you don’t need to edit anything else.
If you do keep the layers because you want to come back and continue editing, make sure you save it as a PSD file.
As you can see, this post-production effect can be very handy if you don’t have a camera or a lens that allows tilt and shift.
Knowing how to focus stack images can be useful for all photographic genres, from landscape photography to macro photography, so I’m sure that sooner or later it will come in handy for you.
If you have any questions about taking the photos and using auto blend and the various other tools in Lightroom and Photoshop, leave a comment below.