What is focus stacking?Focus stacking is an intermediate processing step that combines the use of a camera and post-processing software such as Adobe Photoshop.
Most often, this method is used in landscape and macro photography. Less commonly, portraiturers and wildlife photographers use this method. This method is not applicable when photographing moving objects.
The essence of the method is to create several photos that have different focus points from the foreground to the background. Subsequently, these pictures are mixed together in such a way as to leave the sharpest area from each photograph. This leads to the fact that the photo will be sharp throughout the depth of the frame.
Why use focus stacking?
There are many advantages that this method of creating snapshots gives. To get the desired effect, you need to not only shoot correctly, but also process the photos.
As mentioned above, the image will not be sharp at all depths if you are shooting an object that is located close under the condition of a distant background.
Two focus points were used for this shot. One on the bridge, and the second on the island.
This method also works with macro photography. If you are shooting a small object with high magnification, then the depth of the sharply depicted space will be very small and you will not be able to take a picture so that the whole object is sharp.
Sometimes a slight blur of an out-of-focus area is not noticeable on a smartphone or a small computer monitor, but as soon as you start to print pictures, the difference becomes very noticeable. When printing on large formats, even the smallest errors become visible, and if only half of the image is in the focus area, then printing can be considered a waste of money.
When do you need focus stacking?
Focus stacking can be an incredibly powerful technique, but it is not always necessary. In fact, most likely, you do not need to do this in most cases.
This technique is only useful in a limited list of cases, most of which are already mentioned above:
Photographing a scene with a large distance between foreground and background
Using ultra wide angle lenses when one subject is close
Close-up shot of a scene, for example, a forest, if you want everything to be sharp even with an open aperture
Photographing small scenes and macro photography in general.
To check whether you need to use this shooting method, you can take one shot with the aperture closed to a value of, for example, F / 11, and enlarge the photo to see all the details in the foreground and background. If blur appears somewhere, then this is a good signal that focus stacking should be used.
How to do focus stacking?
It's all just verbal, but how does it really work? Despite the fact that this is an advanced technique, in fact, everything is not as complicated as you might think. Shooting multiple images with different focus points is pretty easy. If you are already familiar with mixing multiple exposures for HDR, the processing will not be difficult for you.
Part 1: Shooting multiple images
Find a place where you can shoot the scene with the foreground and background, far removed from each other. This is easier to do if you place the camera low above the ground on a tripod. It is also not difficult to implement right in your room.
Although this is not very important, it is highly recommended that you use a tripod for this technique. You need to take several photos of the same scene with different focuses. If you move the camera much between frames, problems can occur during post-processing.
Adjust focusAfter you find the scene you are interested in and get ready to shoot, focus on the nearest subject. This can be done either by using manual focus or by selecting the appropriate AF point.
Focus on the closest subject and take the first shot. Then focus a little further and take a picture again. The step will depend on your optics and aperture settings. Usually enough 2-3 pictures in the foreground, in the center of the stage and on the farthest elements.
If you shoot small objects, then there can be up to ten photos. It all depends on the specific tasks, equipment and settings.
Part 2: Focus Stacking and Post Processing
Now that you have taken some images with different focus points, it's time to go back to the computer and mix them together.
The following steps may be a bit confusing for those who do not have much experience working with Photoshop, but following the instructions step by step, the result will be good.
Blending Images in Adobe Photoshop
Adobe Photoshop is the most widely used image processing software.
Photoshop will analyze each individual pixel and select only the sharpest areas in each image before creating a merged file.
Focus stacking in Adobe Photoshop step by step
1. Open the images as layers in Photoshop (If you use Lightroom, select all the images and use the command Change to ...> Open as layers in Photoshop)
2. Select all layers. To do this, click on the top layer, and then hold down the Shift key on the bottom
3. Go to Edit> Auto Align Layers.
4. Duplicate all layers. This may come in handy later.
5. Select the duplicated layers and go to Edit> Auto Blend Layers. (Editing - Auto Layering). Select "Stack Images" and check the box next to Color Mix
6.Photoshop will automatically mix images
7. Zoom in to 100% and make sure each area is sharp
8. If somewhere blurry areas remain out of focus, find in the layers with which the manipulation was not performed the desired image where this area is sharp and add masks to yours with the merged layer.
Focus Stacking at Helicon Focus
Helicon Focus is another software that many photographers use to perform focus docking. This program is created exclusively for this task.
Start by importing files, and then select one of 3 different docking types. Different algorithms can give different results. It is advisable to conduct processing in all three ways and choose the best. For landscape photographs, options A and B are often the best.
While Helicon processes the files, you can see the mask that appears on the screen. Each algorithm will create its own mask. After the rendering is over, you can check the result. Helicon is much faster than Photoshop. If you often use the focus stacking method, this program will save you a lot of time.
Make sure everything went well. The file is ready for export and further processing in Adobe Photoshop, Lightroom or another graphics editor.
There are many different programs that can be used to dock the focus, but Adobe Photoshop and Helicon are the best choice and are used by professionals around the world. There is also another high-level software: Zerene Stacker, which according to some reviews, works better than other programs.
How do you do focus stacking? Share tips or examples of your work in the comments.
About the Author: Christian Hoiberg is a landscape photographer who helps young photographers develop the skills necessary to capture beautiful and impressive images. The opinions expressed in this article are solely those of the author.