Focus Stacking Guide for Landscape Photographers

Have you ever struggled to shoot landscape photos that are tack sharp from the foreground to the background?

Even after you have mastered the fundamentals of depth of field and proper focusing technique, you might still find that some of your images are blurry in the foreground and/or background.

One method to overcome this problem is called “focus stacking,” which involves taking multiple photos at different focus points and then blending them together in post-processing.

This is a technique you can use to increase the depth of field and overall sharpness of a photograph, but it requires more advanced shooting and post-processing skills than other methods.

Before you read this article, I recommend that you first read my Depth of Field Guide here and my Focusing Technique Guide Part 1 here and Part 2 here.

What is Focus Stacking?

Focus stacking is a technique in which the photographer takes multiple photos (usually around 2-5) of the same composition at different focus points, and then combines each of these photos in post-processing using Lightroom and Photoshop (or other preferred software).

This techniques allows you to combine the sharpest regions of each photo, each taken at the lenses sharpest aperture, into a single photo that has a higher overall sharpness and depth of field than could be achieved in a single photo.

Focus stacking can be broken down into two main parts:

1. Capturing photos with different focus points in the field.
2. Blending these images in post-processing.

In this section, you will learn how these two parts work. Later in this article, I will explain the entire focus stacking process step by step.

Part 1: Capturing photos in the Field

The first part of focus stacking involves taking multiple photos of the same composition.

For each photo you focus at a different point in your composition.

Each focus point is chosen incrementally throughout the composition from the foreground to the background (or vice versa).

For example, if you were to focus stack with three photos, you might take:

• a shot with a focus point in the foreground
• a shot with a focus point in the midground
• a shot with a focus point in the background

This type of incremental focusing is called focus bracketing.‍

To capture the scene below in Figure 1, I used focus stacking with three shots at 14mm using an aperture of f/8.

Here is where I focused for the three shots:

1. at the bottom of the large rock in the foreground
2. at the top of the large rock in the foreground
3. about 2/3 of the way in, at the dark green trees in the background

Since each of these three photos had different focus points, they each had a different depth of field.

The first image captured the sharpest foreground, the second image had the sharpest midground, and the third photo had the sharpest background.

Remember:

‍ the sharpest point of an image will be the point you focus on. Sharpness in the image will drop off the further you get from the point of focus.

The depth of field of an image in a focus stack series should overlap with that of an adjacent image (one that has the next closes focus point).

For example, in Figure 1, the image shot at focus point 2 has a depth of field that overlaps with the adjacent images taken at focus point 1 and 3.

It is important to note that front-to-back sharpness of this composition could not be achieved in a single shot using f/8, even if I were to focus at the hyperfocal distance.

The rock in the foreground was simply too close to the camera to get in focus because the depth of field (when using an 14mm lens at f/8) was too small.

You might think that the obvious solution is to increase the f-stop (i.e. close the aperture), however, smaller apertures actually introduce diffraction - a phenomenon that causes images to become soft due to the behavior of light as it passes through an aperture.

This typically occurs at f-stops higher than f/11 or f/16.

For this image, I wanted to keep my aperture at f/8 not only to reduce diffraction, but also because f/8 was the sharpest aperture on the lens I was using. Note: Camera lenses are typically sharpest at 2-3 f-stops above their widest aperture.

This way, I could maximize the sharpness of my final image.

Part 2: Blending Images in Post-Processing‍

When all of the images that comprise a focus stacking series are combined in post-processing, the resulting image is a tack sharp photo that combines the sharpest regions of each photo in the series.

Most landscape photographers (myself included) use Lightroom and Photoshop to blend images in a focus bracket. Jump to: step by step process for merging images in post.

Photoshop has built in tools specifically for focus stacking that will align each of the photos in a focus bracket and merge them into a single photo.

These tools make the process of merging your images very simple.

When Should You Use Focus Stacking?

The truth is, focus stacking is not necessary in most situations.

This technique is not very difficult, but it still requires more work than when you shoot and process a single photo.

Focus stacking is a great option in more rare situations where you don’t have sufficient depth of field to get your entire image sharp with a single photo.

As a reminder, depth of field is primarily determined by aperture, focal length, and subject distance.

In most cases, sufficient depth of field can be achieved in a single photo by correctly adjusting one or more of these settings and by focusing at the right point in your scene (e.g. hyperfocal distance).

Sometimes, however, you still might not be able to get your entire scene sharp and you will need to use focus stacking.

Shooting situations in which focus stacking might be practical:

1. When you accurately focus at the hyperfocal distance but the foreground isn’t sharp. This means that part of your foreground is so close to the camera that there is insufficient depth of field to capture the entire scene.
2. ‍ When you are shooting with a longer focal length lens (e.g. telephoto lens) where depth of field is shallower and it is impractical to focus at the hyperfocal distance.
3. ‍When you want a tack sharp photo by using the sharpest aperture on your lens. If you want to shoot at your lens' sharpest aperture (e.g. f/5.6 or f/8), this will limit your depth of field. Combining multiple images taken at your camera’s sharpest aperture will result in in an overall sharper final photo - even sharper than what you could achieve in a single photo.
4. If you need to maintain a wide aperture in order to speed up your shutter speed and freeze a moving object in your scene. For example, if you are shooting on a windy day and parts of your scene are blowing around, such as flowers or tree leaves, you will need a fast shutter speed to freeze the image and prevent the scene from becoming blurry. In order to balance the exposure triangle, you will need to open your aperture (and/or increase ISO - which is not recommended if you want the sharpest possible image). Since a wide aperture will reduce depth of field, you might not have sufficient depth of field to get the entire composition sharp without focus stacking.

How to Focus Stack Step by Step Part 1: Shooting in the Field

1. Set up your camera on a sturdy tripod. This is very important because you want each frame to match. The only difference between images should be the point you focus on, so a tripod will keep your camera in the exact same place for each shot.
2. Compose your photo. Double check that your camera is level.
3. Set your white balance and exposure settings. I recommend that you shoot in aperture priority mode at your sharpest aperture (e.g. f/8). Shooting in manual is also an option. You just want to make sure that your f-stop stays the same in each shot of your series. It’s okay if shutter speed varies between shots because you can fix exposure variations between shots in post-processing.
4. Using single point autofocus, focus on an object in the foreground and meter the scene. I recommend using back button focus to focus and Live View to view your composition and focus point. This will allow you to zoom in and ensure that the foreground is sharp. It can also be very helpful for you to understand how to use a histogram to ensure that you have the proper exposure for each image.
5. Press the shutter button and capture the photo.
6. Review the photo on the camera’s LCD to ensure that the foreground is sharp and properly exposed. Retake the photo if necessary.
7. For the second image, move the focus point to an object in the midground.
8. Do not move the camera or change any of the settings (e.g. keep the f-stop the same).
9. Refocus at the point you selected in the midground.
10. Press the shutter button and capture the photo.
11. Review the photo on the camera’s LCD to ensure that the foreground is sharp and properly exposed. Retake the photo if necessary.
12. Repeat steps 7 through 11, this time moving your focus point to the background.

If you find that you can capture sufficient depth of field with three images, you may need to take additional photos while focusing at more points throughout your composition.

This is unlikely, however, because when shooting at f/8 or f/11, you really shouldn't need more than a few images, even with longer focal length lenses.

Like I mentioned before, it important to test your lenses at different settings so that you have a better understanding of how many photos should be sufficient for your particular settings and set up.

How to Focus Stack Step by Step Part 2: Post-Processing

Note: this is not the only way to merge images, but it is one of the easiest ways to do it.

1. In Lightroom, open the images in your focus stacking series; the ones you captured in Part 1 above.
2. Select the image that is exposed for the brightest part of your scene.
3. Develop this photo by adjusting exposure, color, contrast according to your taste.
4. Once you are finished developing the first image you selected, hold down command (if you have a Mac) or Alt (if you have a PC) and select the other images in your focus stack series.
5. Click “Sync” on the right panel. In the dialogue box that pops up click check all and synchronize. This will apply the adjustments that you changed in the first image to the other images in the series
6. Alternatively you can sync setting by right clicking the selected images and then clicking Develop Settings > Sync Setting. In the dialogue box that pops up click check all and synchronize.
7. Next, it is important to match the exposure of the first image you selected to the other photos in your focus stack series. This will make exposure consistent across all images and make them easier to blend. To do so, while all of your photos in the series are selected, go to Settings > Match Total Exposures
8. The next step is to open all of your images in the focus stack series in Photoshop. To do so, while still in Lightroom, right click on your selected images (make sure they are all selected) and click Edit In > Open as Layers in Photoshop. This will open each photo as an individual layer in Photoshop.
9. Select all of the layers that just opened in Photoshop (hold command - if you have a Mac - or Alt - if you have a PC while you click each layer in order to select them all).
10. Go to Edit > Auto-Align Layers. Select Auto and then click OK. If your camera slightly moved between shots, this will perfectly align each photo/layer.
11. Time to blend your images. Go to Edit > Auto-Blend Layers. Then select Stack Images and click OK. This will result in a new layer added to the layers panel. This layer is your merged image which should be sharp from front to back.
12. Merge all of your layers. You can do this by selecting all layers in the layers panel. Then right click on the selected layers and select Merge Layers.
13. Finally, you may need to crop the borders of your final image just slightly because they can get messed up during the aligning and blending process.

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How Many Photos Should You Take When Focus Stacking?

The number of shots you take will depend on the depth of field you have in each individual shot.

There is no rule or “correct” number of photos that will work.

The number of photos you need to take in order to focus stack will vary from one image to another depending on your settings and your composition.

• If your camera settings give you a relative wide depth of field (e.g. a wide angle, small aperture, and/or subject is far away), then you will probably only need 2 or 3 photos in your bracket.
• If your settings give you a relatively shallow depth of field (e.g. a telephoto lens, wide aperture, and/or subject is close) then you will likely need more than 2-3 shots.

What is important is that you don't change focus too much between shots.

For example, let's say you take two photos for a focus stack. You focus on the foreground in one photo and the background in another photo. If neither of these images capture enough of a focused midground, then your images might not blend well when they are merged in post-processing.

It is also important to test your gear and settings to see how many shots you actually need. It may take some experimentation to get right!

I recommend taking the fewest number of photos necessary to get a sharp final photo. When I focus stack, I typically only take 2-3 photos.

The more photos you have to merge in post-processing, the more complicated things will get.

Simpler is always better.