We’re certainly not the first to entertain this idea, but while most people associate focus stacking with macro photography (at really high magnifications one’s depth of field (DoF) can be 0.05mm, or less) focus stacking can have value in architectural and landscape photography, even product photography as well. It’s something I’ve only recently tried so I thought I’d share some experiences.
For any image there’s one point (at most) in the frame that is in exact focus. Depth of field is the range of distances within any particular image that appear to be in focus. We’re not going to weigh you down with the details, like Circles of Confusion, Scheimpflug principle, etc. There’s more than enough information on that available on the web.
Focus stacking is a process whereby one takes a series of images with different points of focus and then uses software to choose sections of each image to create a composite image. Here’s an example: