How to do Focus Stacking in Photography
Shallow depth of field is great and all but there are certain scenarios where you want essentially all of the scene in focus. Think about when you photograph products, macro photography, or even landscape photography. Details matter a lot in those cases. So how do you go about taking such sharp photos?
Using narrow apertures is an option, but when you close down the aperture too much, diffraction creeps in and makes your images softer. The ultimate solution is thus to use a technique called focus stacking.
Focus Stacking Technique
The process of stacking photos involves shooting a series of images across a focal range. So you end up with a series of images with each part of a subject in focus. Using this technique, you take multiple images of the same subject or scene by shifting your plane of focus in each photo. Once you’re done taking the photos, you can use software to stack them all up and obtain a single final image that’s sharp from front to back.
You can follow these steps for focus stacking:
•Set your camera up on a tripod and compose your shot. Once set, make sure that the composition doesn’t change at all. If that happens, you’ll need to start all over.
•To make sure that all the images come out consistent, also make sure that no camera settings and lighting changes. In the case of landscapes, you’ll thus need to be quick. Start off with an aperture that has a good depth of field, like f/8, choose a shutter speed based on the lighting (but not too slow), and use a low ISO value for a clean and detailed image. Feel free to adjust the settings as per your requirements.
•The only thing that you will be changing in this process is the focus point. Start by placing your focus point at the front or the back. After every shot, move the focus point a bit closer to the opposite end. Continue this until you reach the other end of the scene from where you started.
Once done with these steps you should end up with a handful of photos. The exact number will vary depending on the subject. The next step is to load the images all up in Photoshop and get the final sharp image:
•Ensure that all the images are saved to the same folder.
•In Photoshop, go to File>Scripts>Load Files into Stack…
•Browse for your images and with the “Attempt to Automatically Align Source Images” checked, click OK. This will get rid of any small misalignments caused due to any movement of the camera or subject.
•Next, Photoshop will align and load all the images in layers. Select all the layers and go to Edit>Auto-Blend Layers…Select Stack Images and hit OK.
•Photoshop will now analyze all the images and mask out all those parts in the image that appear soft or blurry. The final image will thus appear in focus from front to back.
When using this technique there are chances that the stacking process may not do a 100% great job. If that happens, you can dive in for yourself and adjust the mask manually.