Focus Stacking
During this quarantine time, I’ve explored my hobbies a bit deeper. With photography, that means learning different techniques and trying them out. Today, we’re going to look at focus stacking – a technique which can give crisp images without sacrificing aperture. Sometimes, when shooting with a narrow aperture, like f/22, chromatic aberration can affect an image. Also, if you want to normalize bright lights and get an evenly lit image without shooting with neutral density filters, focus stacking can help. The idea is that you bracket your focusing to take a series of images with different planes of focus, then stack them at the end to create a crisp image. Tip: check your camera to see if you can set this up automatically!
Here’s an example stacked image, consisting of 15 individual shots, I took of some books:
Without stacking, here’s what the image would look like using the same settings (f/5.6, 30mm, ISO 200, 1sec exposure time):
If I tried using a large depth-of-field, such as f/11 or even f/22, here’s what the image would look like:
Shot at f/11, 30mm, ISO 200, 1sec 
Shot at f/22, 30mm, ISO 200, 4sec
My goal was to get the entire scene in focus. Seeing as shooting a single frame wouldn’t do the trick here, I used focus stacking. Here are the steps.
Step 1: Load Files into a Stack
I am currently using Adobe Photoshop CS6 to stack my images. The first step is to load the images into a stack by going to File > Scripts > Load Files into Stack.
Step 2: Align Images
Next, align the source images by checking the “Attempt to Automatically Align Source Images” box, then click “OK”.
Step 3: Check the Layers
The next step is to wait for the layers to load and align. On the right, you can see the images opening as layers. Depending on the number of images you’re loading, this may take a few minutes!
Steps 4 and 5: Blend the Layers
Now it’s time to blend the layers. To do this, go to Edit > Auto-Blend Layers.
When the “Auto-Blend Layers” dialog box pops up, select “Stack Images” and check “Seamless Tones and Colors”, then click “OK”.
Step 6: Flatten and Crop
Finally, clean up the image by flattening the image (Layer > Flatten Image), then crop the image as you see fit.
Here’s the final image (I shot these photos using a 30mm f/3.5 macro lens):
Quality Control
When using the focus bracketing feature on my camera, I always use a tripod. But even with a tripod, the more images to be stacked, the more likely there will be some noise that’s introduced. Looking at the following image, you might notice the fuzziness around all 4 edges of the photo:
To ensure that the final image is cleaner, I had to make a slightly tighter crop:
Examples
Here is a stacked image of the blinds in my house. Again, I shot this with my macro lens. Look at how clean the final image looks!
I have a Hot Wheels car with Toad driving it, and decided to create a stacked image of that, just for fun:
Final Thoughts
Focus stacking isn’t just for macro photography. It can be used in landscape and portrait photography as well. Although some tweaks need to be made, the concept is the same. I’m still getting the hang of it, but I hope this guide helps!