How To Easily Focus Stack In Photoshop
Focus stacking is a technique that allows you to achieve a deep depth of field in a final image by blending (or stacking, as it’s often referred to) several images together. The idea is that you take several shots of your subject, each focused on a different spot. Once you combine the images in Photoshop, you’ll end up with a perfectly sharp, in-focus subject.
Why might you want to use this technique?
Well, consider this shot I recently did:
I shot this image at a longer focal length (105mm) and a narrower aperture (f/4.0). I made these decisions because I wanted to throw the background completely out of focus so it would be easier to clean up my black background, giving me the desired effect.
The problem with shooting in this way is that a single frame would not get the entire camera in focus. Just take a look at this example, which is focused on the back viewfinder:
The back viewfinder is tack-sharp, but the rest of the image is soft.
Once stacked, I should end up with a perfectly sharp subject!
Focus stacking with Photoshop
There are several ways you can go about focus stacking, but I will be showing you a technique to easily do it in Adobe Photoshop. The first step, of course, is to load your images onto your computer. You could also make individual adjustments to each frame if you so desire, but I’m not going to be covering that here. Once the images are loaded up, open up Photoshop.
From here you want to go to the File menu, select the Scripts sub-menu, and choose the Load Files into Stack option.
This will open a small window entitled Load Layers. Click the Browse… button.
This will bring up an Explorer window (or a Finder window, if you’re on a Mac) where you can navigate to your frames. Select all the ones you want to load and choose Open.
You should see your list of images listed in the dialog now. From here you can go ahead and click the OK button. Note that you can choose to check the box to attempt automatically aligning the source images, but I prefer to do this as its own, separate step.
From here, Photoshop will take a couple of seconds to load all of your selected images into a separate layer. From here, select all of the layers (you can just select the top layer and then click the bottom layer while holding down the Shift key on your keyboard). Go to Edit and choose Auto-Align Layers… (Note that this is a step you could skip if you chose this option in the Load Layers dialog. My personal workflow just has it as its own step).
You’re finally ready for the final step of the stacking process! Once Photoshop finishes its auto-alignment magic, keep your layers selected. Go back to the Edit menu and choose the Auto-Blend Layers… option.
This will open a small dialog. The defaults here should be all you need. Simply hit the OK button and Photoshop will chug away and do its magic!
How long this process takes will depend on several factors, including how many images you loaded, how big each file is, and on your particular computer hardware. On my reasonably powerful desktop, however, it typically only takes a few seconds.
Regardless, assuming everything goes well, you should see that Photoshop auto-applied layer masks to your individually loaded frames. It also helpfully created a merged copy of these layers, which it places at the top of the layers panel.
I like to group the original, masked layers together in a folder called something like “stack files” and then hide the group. This is highly dependent on your own work style, however.
No matter how you like to work from this point on, you should have a beautifully blended image with your subject fully in focus! From here, you can do whatever editing you’d normally do to finish out your image.
My finished, fully-edited result
That’s all there is to it!
As you can see, this method for focus-stacking images is quite simple. The beautiful thing is that Photoshop’s algorithms have advanced to the point that it’s able to auto-align and auto-blend most subjects without any trouble!
I’ll leave you with one more example of where this technique can shine, which is with macro photography. Anyone who has ever tried to shoot macro knows that achieving the proper focus with the narrow depths of fields involved is one of the biggest challenges. This often means that focus stacking is essential to get the result you’re after.
Here’s an example of a macro shot that I used focus stacking to achieve:
If you found this guide useful you may also want to check out my other free guides to photography and wilderness skills.
