create razor sharp images with focus stacking

Focus Stacking: How To Create Front-To-Back Sharpness In Your Image

If you love landscape photography as I do, then you must know (if you haven't) focus stacking.

Don't get intimidated by its technical name though. 

Focus stacking essentially means...you may have already guessed it right..

Stacking images with different focus...to improve the quality of the image.

how to create razor sharp images with focus stacking

In this post, I'm going to explain why you should care about focus stacking and how to do it in the most efficient way.

You'll see just how easy it is to do it yourself.

The Challenge

Let’s look at two classic scenarios where focus stacking is used to improve image quality.

Scenario 1

You're right in front of an incredibly stunning landscape.

There are beautiful wildflowers where you are. It extends all the way to the mountains in the back.

The mountains look like giants guarding the land, forming the perfect horizon for the sun.

foreground out of focus - focus stacking

You took a shot.

No matter how hard you try, the wildflowers immediately in front of you are always out of focus.

What’s going on and what should you do? (we’ll answer this question later in this post)

Scenario 2

Let’s take the wildflower scenario again…

Except for this time, there isn’t anything out of focus in the immediate foreground.

You look at the scene...the mountains go all the way far back and merge with the sky.

The first thing that pops into your mind is hyperfocal distance…

You take out your smartphone, open the app and calculate the hyperfocal distance.

Then, you press the shutter release and thought you’ve nailed it!

focus stacking hyperfocal distance

But little did you know, when you view the image large on your computer, the mountains in the back are not as sharp as the foreground.

Sounds familiar?

What Is Focus Stacking?

Also known as focus bracketing or focus blending.

The concept is similar to bracketing exposure.

But in this case, the subject, composition and exposure settings remain constant throughout the shot.

What you change is the focus point.

You shoot a series of bracketed shots, each with a different focus point.

These images are combined in post-processing to create a single image. 

focus stacking

Use focus staking to achieve front-to-back sharpness

The purpose of focus stacking is to maximize the sharpness from the foreground all the way to the background without missing a spot!

In a way, the focal point of the image is “extended”. 

Remember the example in scenario 1? 

The immediate foreground is out of focus because it's too far away from the focus point. (the amount of "out of focus" is also depends on the focal length and the aperture).

But this can all be resolved with focus stacking.

Why Use Focus Stacking?

There are two reasons why camera techniques are invented.

One, to allow us to fully utilize the features of digital cameras to produce the desired image.

Second, to help us circumvent the technical limitations of our gear to capture better images.

For focus stacking, it’s the latter.

To dive in further, here are four main reasons how focus stacking benefits you:

1. Achieve Front-To-Back Sharpness

sharpest aperture

Image source: bobatkins.com

With focus stacking, you can achieve focus point sharpness for the entire image.

Technically, this is impossible even with the best of the best lens.

Camera lenses can only focus a single point. The sharpness of the image from there onwards is completely dependent on the aperture and focal length...

...each lens also has an optimal aperture (sweet spot!) where the image produced is at its sharpest.

Beyond that, it will suffer from diffraction and sharpness starts going down the slope.

2. Get The “Fresh Look”

Remember those shampoo TV commercials?

Whenever the camera zooms into the model’s hair, it always looks in focus (sharp!), shiny and kind of wet.

You can almost see every single stand so clearly...

Subconsciously, our mind tells us “wow, what a fresh look!”.

When we see a tack sharp photograph, we recall the same subconsciousness and therefore the same impression.

This is further reinforced and enhanced when we use focus stacking to maximize sharpness.

3. Extended Depth-of-Field

Depth-of-field (DoF) is the distance between the closest and the farthest object that appears sharp in the image.

There are two universal limitations to DoF:

  1. Object very close to the lens will often be out of focus (also dependent on focal length and aperture). 
  2. Although objects within DoF appear sharp, it actually falls off gradually as you move into the distance from the focus point even at the optimal aperture.

This becomes a technical issue when there’s a great distance between the foreground and the background. (scene with great depth)

With focus stacking, you can extend the DoF of any lens to make both the closer foreground and the background equally sharp as the focus point.

extended depth of field focus stacking

4. Macro Photography

Macro photography is technically challenging.

It’s nice to get a glimpse of life beyond what the human eye can see…

But to capture a meaning image require more than just a macro lens.

Also, light is an issue in macros…

...and most macro shots are done with a wide-open aperture to maximize ambient light for exposure.

macro photography focus stacking

That means trading off with DoF.

If you’re shooting a busy bee harvesting honey, you might only get its little head or wings in focus.

To get the entire subject in focus...yup, you got it…

Focus stacking!

Equipment You Need

It’s pretty simple really.

  • A camera capable of shooting in manual mode and a lens with manual focusing (which you probably have already if you’re reading this article).
  • A tripod - Unlike exposure bracketing where you can shoot with handheld, it’s impossible to focus stack without a tripod.
  • Software - You need a software to blend the bracketed images together. This will be discussed in more detail in post-processing.
  • Patience - I don’t want to put you off by saying the workflow is tedious...but it does take some practice to get used to it and become efficient. The bottom line is, be patient on your first few attempts!

How To Bracket Focus

A common challenge for beginners is not knowing where to focus when bracketing focus.

Here are three different ways to bracket focus.

The first two techniques share the same principles, just different ways of execution.

The third method applies to Canon users only 🙂

The Vertical Line Technique

The way I do it, I follow an imaginary vertical line so there’s no confusion!

Here are the steps:

  1. 1
    Mount the camera on a tripod, compose the image.
  2. 2
    Switch on and use live view (if you normally use the viewfinder).
  3. 3
    Switch to Av mode and set the desired aperture.
  4. 4
    Use matrix/evaluative metering and take a shot. Note the ISO, aperture and shutter speed.
  5. 5
    Switch the camera to manual mode, dial in the exposure settings from above.
  6. 6
    Switch the lens to manual focusing.
  7. 7
    Draw an imaginary vertical line from the bottom to the top of the frame. Ideally, you want this vertical line to cross the entire depth of the image.
  8. 8
    Zoom in on the LCD screen and start at the bottom of the frame. Turn the focusing ring until the objects are in focus. Take a shot.
  9. 9
    If your camera has arrow buttons, use the up button to move up the frame up along the imaginary vertical line until objects become out of focus. At this point, turn the focusing ring to focus again. Take a shot.
  10. 10
    Repeat step (9) until you have reached the furthest point in distance within the composition.
focus stacking vertical line technique

Red line represents the imaginary vertical line. Round dots are focus point.

With this technique, you literally won’t miss a spot.

The image will be guaranteed to be tack sharp throughout.

The Minimalist

Similar to the vertical line technique, the minimalist requires only three bracketed shots.

Start by following Step 1 to 6 above…

Instead of taking multiple shots with different focus points along an imaginary vertical line, you only need to focus the foreground, midground and the background.

focus stacking the minimalist technique

Focus point (red dots) in foreground, midground and background.

The principles are the same, do it on the LCD screen (live view), in manual mode and manual focusing.

This technique does save you some time, but the main disadvantage is the potential of less coverage.

Magic Lantern

This is for Canon users only.

Unfortunately, there isn’t an equivalent version for other cameras.

Magic Lantern is a free software that adds a whole lot of additional features to your Canon EOS cameras.

One of the many features is focus stacking, which you can check it out here.

Essentially, you can programme your Canon EOS camera to bracket focus automatically.

I won’t go into detail but you can read all about it on their website.

Post-Processing

This is where the magic happens.

There are two parts to it: (1) Align the images, and (2) Blend the images.

I use Adobe Photoshop CC 2019. If you use other software or an earlier version, the steps might be slightly different but the principles are the same.

How To Align Images

Before merging the bracketed images, you really want to make sure they are aligned perfectly.

“I used a tripod, why would they not be aligned?”

Great question!

Did you know that changing focus distance changes the focal length slightly? A phenomenon called focus breathing.

Because we are constantly changing the focus point, the images are bound to be NOT aligned.

To align the images, you can use Lightroom + Photoshop or Photoshop alone.

I’ll explain both.

Lightroom + Photoshop Workflow

The reason for using both is simple.

Lightroom for organization and light editing, Photoshop for the heavy lifting.

Once you have highlighted the images you want to align in Lightroom, right-click and select Edit In > Open as Layers in Photoshop.

In Photoshop, select all the layers and go to Edit > Auto-Align Layers.

auto align layers for focus stacking

Select Auto in the Auto-Align Layers panel.

You can also check the box for Vignette Removal and Geometric Distortion if you haven't done so already in Lightroom.

Photoshop Workflow

If you don’t use Lightroom or have another software for organizing your images, you can first export them into a folder or desktop for the moment.

In Photoshop, go to File > Script > Load Files Into Stack.

stack layers in photoshop for focus stacking

Browse to select all the images and hit OK.

The rest are exactly the same as explained above.

How To Focus Blending

Once you have aligned the images, the rest is really easy.

By now, you should have all the images for focus stacking aligned and stacked in layers in Photoshop.

If, for any reason, you have deselected all the layers...select them all again.

Now, go to Edit > Auto-Blend Layers.

auto blend layers in photoshop for focus stacking

The Auto-Blend Layers panel pops out at this point.

Select Stack Images and keep the other two options below checked (as shown in the screenshot above).

Depending on how many images you have, this might take a while.

Just sit back and relax…because the hard work is done!

Other Software/Apps For Focus Stacking

Not to worry if you don’t have/use Lightroom or Photoshop…

There are other software you can use to blend bracketed images for focus stacking.

Here’s a list of what’s available out there. 

Some are editing software (like Photoshop) with focus stacking feature, some are software designed for focus stacking only:

Lastly, apps. 

Apps are no longer just games that we play to kill time...

There are plenty of useful apps that can be great tools to help us do things better.

Lucky for us, FocusStacker (IOS only, not to be confused with Focus Stacker mentioned above) allows you to calculate how many bracketed focus you need for a give aperture.

It completely takes away the guessing/trial and error to speed up your focus stacking workflow.

Final Thought

If you ever wondered how to achieve front-to-back razor-sharp images in landscape or macro shots, focus stacking is the answer.

It has a rather small learning curve...and you can definitely streamline the workflow with a bit of practice.

Also, post-processing is rather easy compared to, for example, exposure blending.

How To Focus Stacking (In Summary)

Here' a quick run-through: 

  1. 1
    Mount the camera on tripod, Av mode, matrix metering and take a shot. Note the exposure settings
  2. 2
    Switch both camera and lens to manual and dial in the exposure settings from above.
  3. 3
    Using the LCD screen (live view), take a series of bracketed focus using the vertical line technique or the minimalist technique.
  4. 4
    In post-processing, stack the images in layers to align them.
  5. 5
    Blend the images to combine focus. (Auto-Blend Layers in Photoshop)
  6. 6
    Save the focus stacked image and do further editing.
  • Jack says:

    Just finished taking 17 shots for focus stacking when I see I had an email, did exactly as you suggested and now going to import into PS and let the work begin!