A lot of landscape photographers are interested in focus stacking — combining multiple images of the same scene, each focused at different distances, into a single photo. This is a useful tool to have at your disposal, since it lets you take pictures in more situations than you otherwise could. For example, if elements of your photo are very close to your camera, focus stacking may be the only way to get a sharp shot. Although I don’t use this technique for every photo, it’s something that I keep in mind when I’m taking pictures in challenging conditions. This article gives an overview of focus stacking for landscape photography, including step-by-step instructions on how to focus stack photos in Photoshop. All of these tips are also relevant for other types of photography, not just landscapes.
1) What Is Focus Stacking?
Focus stacking is an interesting development of digital photography, and, more specifically, digital post-processing.
Focus stacking lets you take several photos of a landscape, focused at different points, and combine them together into the sharpest possible image. For example, you may take three photos at a particular scene: one focused on the foreground, another on the middle-ground, and a third on the background. Then, you can take the best parts of each photo and combine them into a fully-focused image.
(The latest installment in “Spencer can’t draw, but a diagram here would be useful.”)
You can focus stack with any lens and camera, but you need to have the right post-processing software to combine the photos together. I use Photoshop, since that’s what I already own, but there are better programs out there if you do a lot of focus stacking — Helicon Focus and Zerene Stacker being the two main products. However, if you only do occasional focus stacking, Photoshop’s tools should be fine.
2) Why Focus Stack?
There are two main reasons why you might want to focus stack a landscape photo.
First, you could be photographing a landscape that has too much depth. In other words, some parts of the scene are too close to your camera, and they’re out-of-focus if you shoot just a single photo. This can happen if your foreground is very close to your camera — there’s just no way to capture a focused foreground and background in one shot (even at small apertures like f/16).
You’ll also run into sharpness problems when you use telephoto lenses for landscape photography. Because they have such a thin depth of field, telephoto lenses will cause some blurriness in all but the most distant landscapes. Again, even an aperture of f/16 may not give you enough depth of field.
For me, that’s the most common time that I use focus stacking — when there’s no other way to get enough depth of field. In fact, I shoot most of my focus stacks at f/16, since it means that I don’t have to take as many photos (more on that later).
However, there’s also a second reason why some photographers focus stack, and it’s equally valid.
Because all lenses have a sweet spot, there will be an aperture that gives you the sharpest possible photo. For a lot of lenses, this sweet spot will be somewhere from f/4 to f/8. Unfortunately, those apertures don’t always give you enough depth of field, so you have to compromise.
Or not — that’s the other reason to use focus stacking. If you want the absolute highest image quality of a given landscape, you can use your lens’s sharpest aperture and stack together as many shots as you need. The downside, of course, is that you need to take several photos per scene to capture all the depth of field.
In the end, you should only focus stack if you require more detail than the camera can capture in a single photo. You might create huge prints, do a lot of cropping, or work with landscapes that have an unusually large depth of field. Regardless, focus stacking helps you get the last little bit of image quality that you can.
3) When Can You Use Focus Stacking?
Of course, nothing is a free ride. On one hand, compared to a single photo, focus stacking takes up more time and memory card space. Plus, not all landscapes even work for focus stacking.
For example, think about a wave rolling into shore. It’s not a problem to take a single photo, but focus stacking is essentially impossible — the wave will move too much from frame to frame. This is true in many landscapes with fast-moving subjects. The more quickly a scene changes, the harder it is to focus stack.
If the landscape isn’t moving too much, though, you can focus stack most of the time. Of course, this is only true if you’re willing to go through the effort of capturing multiple photos at once. The more often that you focus stack, the longer you need to spend working on every shot you take — both in the field and in post-processing. If you use focus stacking 100% of the time, you’ll run out of space on your memory card much faster than usual.
That said, if you have to use focus stacking, it’s a great tool. Don’t avoid it just because it takes time; in the end, it’s worth the effort for certain scenes. So, how do you focus stack? That’s covered in the next section.
4) How to Focus Stack Landscape Photos
Focus stacking isn’t hard, but it definitely requires more effort than when you take single photos.
To start, you need to employ best practices in the field. What does this mean? Quite simply, you have to take photos in a way that your stacking software can recognize easily.
First, you should use a tripod. Although it’s possible to shoot handheld focus stacks, it will increase the likelihood of difficulties in post-processing.
Second, make sure that you don’t change the focus too much from shot to shot. For example, if you only take two photos — one focused on the foreground, and one on the background — the middle of your photo could be blurry! Even if your post-processing software still blends the shots together, the final image won’t look very good.
When you’re in the field, it’s best to focus on the exact spot in the prior image where sharpness first starts to decrease. You might need to zoom in on live-view in order to do this properly. By doing this, you avoid an unnatural-looking final result.
Now that you’ve taken your photos, it’s time to start blending them! Here, I’ll demonstrate how to focus stack in Photoshop, since that’s the software you’re most likely to have. (If you have Zerene Stacker or Helicon Focus, you’ll have a bit more control over the process.)
Before you open the photos in Photoshop, you need to make sure that they are ready to merge.
Specifically, ensure that the brightness of all your photos is the same — otherwise, they won’t merge properly. Normally, this won’t be a problem, but you might notice a brightness difference if the light was changing quickly from shot to shot.
The photo below(along with six other photos focused at different distances) is part of the focus stack that this article covers. I took these images at f/5.6, which makes it easier to see the thin depth of field:
NIKON D800E + 70-200mm f/4 @ 92mm, ISO 100, 1/8, f/5.6
Here’s the focus stacked result (unedited — final version at the bottom of the article), where everything is incredibly sharp:
This is the unedited version of the final focus stack. You can see how much sharper it is than the prior photo — click on the two images if you want to compare them larger.
5) Focus Stacking Checklist
Now that you’ve taken your photos, it’s time to bring them into your post-processing software. Here’s a quick checklist that can help if you use Lightroom and Photoshop:
- First, open all of the images in Photoshop. You can do this by entering Lightroom, highlighting every shot, then clicking “Open as layers,” as shown below:
- Once your photos are in Photoshop, select all the layers, and click Edit > Auto-Align Layers. In the next window, you can leave the blend mode to “Auto”:
- Now, click Edit > Auto-Blend Layers, and then “Stack Images,” as below:
- Click Layer > Flatten Image. Save the photo by clicking Control + S (Windows) or Command +S (Mac), or just File > Save. That sends the completed version back to Lightroom:
- Open Lightroom again. Now, you need to crop the photo so it looks good. Often, the edges of your image will have large sections that are extremely blurry — you need to crop those out. Here’s how that looked for this particular focus stack:
- Finally, once you’re done cropping, just clean up the image and edit it however you want! There’s no wrong way to proceed from here. You’ve already created a focus-stacked image.
6) Conclusion
Although focus stacking isn’t something you should do all the time, it’s an important tool to have at your disposal.
Sometimes, you may use a telephoto lens and have difficulties getting everything in-focus. Or, you could have a landscape that stretches so far that even f/16 doesn’t have enough depth of field. Finally, if you’re interested in nothing but the top sharpness, you might focus stack a landscape simply to use your lens’s sharpest aperture (like f/5.6 or f/8) rather than a smaller aperture which has diffraction.
There is no right or wrong reason to focus stack, but be aware that you can take this technique to levels that might not be worth the effort. When I first learned about this focus stacking, I tried to use it on every landscape that I shot, simply to get the sharpest photos. Unfortunately, this meant that each photo took five times longer to capture! I ended up with sharp photos, but I didn’t get as much variety in my shots, and my work suffered as a result. Now, I’m more likely to use f/16 than to focus stack at f/5.6. If focus stacking works well for your personal style, though, that’s great — don’t let me discourage you. It just isn’t the case for everyone.
Hopefully, this helped provide a good platform for you to start focus stacking your own shots! If you haven’t tried it before, give it a go. For certain difficult landscapes, focus stacking is an incredible tool.
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