Much of photography develops creative ways to break the boundaries of the laws of physics. One of these techniques is Focus Stacking.
Even wide-angle lenses in narrow apertures-a combination that provides the greatest possible depth of field-can not sharply focus both the extreme foreground and the extreme background. They may come closer, but if you have a cool shell in front of you and something else in the distance is interesting, one or both of them will be a bit blurry. Look at this photo.
Even if it is not bad, the shell is less sharp than I would like, while the castle is in focus on the island, or as much focus as mine can setup.
Here's a picture I focused on the shell instead.
While the web resolution looks very similar when you zoom in on the high-resolution file, you can see that the shell is sharply focused – look at the rings around the shell and the small pebbles nearby to see them – while the castle is not on the island.
Here it is Focus Stacking comes into play. This technique combines multiple frames in a single composite image with a depth of field that is not possible in real life. Here I stacked the two photos above.
Take a closer look, and both the shell and the castle are sharp.
Fine, right? Let's see how it works. I will demonstrate this with Photoshop, but you should be able to reproduce this technique in most good image editors.
When is the focus stack used?
The focus stack is useful whenever you want depth of field in your area. Images that you can not optically receive. This is especially true when you are shooting landscapes where something happens both in the foreground and in the background, as in the above example, or when you are doing macro photography. The rest of the time, you do not have to use the focus stack because the lenses and camera provide sufficient depth of field.
Recording for focus pile
The focus pile starts with the camera. If you do something wrong here, your recording will not be saved by Photoshop work.
Begin working through your normal process and dialing the correct exposure settings. Eventually, you'll find that you need to use Focusstacking to focus everything.
When you have your final composition set, fix the camera on a sturdy tripod and switch to manual exposure. You want to make as few deviations as possible between the two shots.
RELATED: How to Manually Adjust the SLR or SLR Camera
Next, go to Manual Focus Mode. This is one of the situations where you get the best results from doing things by hand. Turn on the live screen and zoom in to the maximum (usually 10x) in the foreground. Turn the focus ring until it looks as sharp as possible, and then take your first shot.
Next, you can use the live screen to enlarge the wallpaper. Focus again and take your picture.
Two frames are usually enough, but if you work with wider apertures or just want to be sure, you can take a third picture and focus somewhere in the middle -ground.
Focus stacking of images in the post
If you want to do a lot of focus stacking or mix a dozen frames to get perfect macro shots, you should consider special focus stacking software like Helicon. It is designed for use in extreme situations. But if you want to increase the depth of field in your landscape shots, you'll probably be fine with the image editor you already use. I will show it with Photoshop. To follow, you need to be familiar with how layer masks work. If not, read our full guide to layers and layer masks before proceeding.
RELATED: What are layers and masks in Photoshop?
Open all the frames you want to mix into a single document. In Photoshop, go to File> Scripts> Load Files to Stack. Click on "Browse" and select the files. Select the "Automatically align source images" check box – this will fix small swaying situations – and then click OK.
Since the differences between the two images are likely to be quite small, I recommend them. Zoom in to 100% and rename the layers so you can easily remember which layer is where. I like to put the plane where the background objects are in focus at the top, but it does not make much of a difference.
Select the top level and go to Layer> Layer Mask> Show All.
Select the Brush tool (the keyboard shortcut is B), and make sure you have a nice, big, soft brush.
Select the mask and start painting black over the areas of the frame that are slightly out of focus. I disabled the lowest level to give you an idea of where I want to mask.
Zoom in, switch back and forth between layers, and mask things so everything between the two blends frames beautifully. If necessary, you can use advanced selection tools.
When you're done, you should seamlessly put the two frames together into a single image with extended depth of focus.
Focus stacking is probably not something you often need to use, but it is a useful technique to know about it. Just make sure things are right on the spot.