What is focus stacking?
You may have looked at a scene with your eyes and wondered why it looks different in the photo you took. This is because, especially with a longer focal length or a shallow depth of field, not everything in a single image can be in focus at once. Whereas your eyes immediately adjust their focus as you look from area to area, a photo must focus on just one area at a time. Professional photographers use a technique called focus stacking to portray multiple objects in focus on various focal planes in one sharp image where everything is in focus, essentially mimicking a greater depth of field without any loss of definition.
Focus stacking can be a key tool in product photography, macrophotography, landscape photography, and other areas where a sharp focus across the entire image would make your photo stand out. “The goal of focus stacking is to take a photo of as many in-focus slivers as you can and then Photoshop matches them together into a fully in-focus composite image,” explains photographer Nick Ulivieri. “It looks more polished, more real. So real, it almost looks fake.” In Adobe Photoshop Lightroom, you can focus stack by using Auto-Blend Layers on several images to create one final image with crisp lines.