Focus stacking (or hyperfocus) is an image stacking operation that combines multiple images taken at different focal distances to give a resulting image with a greater depth of field (DoF) than any of the individual source images. Focus stacking can be used in any situation where individual images have a very shallow depth of field, e.g. macro photography and optical microscopy. In the example below, we have 2 images of a scene containing a hairbrush and a wristwatch (on the left) taken at two different focal points:
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In the first image, the wristwatch is in sharp focus but the hairbrush is out of focus, while in the second the reverse is true. The image on the right shows the result of running Focus Stacking on them. Chasys Draw IES examines the images, identifying the level of focus for each pixel. It then combines the pixels that have been identified as the most “focused” to create the final image.
The “how” bit
You need at least 2 same-size images of the same scene to run this engine. The idea is to take several photos the same scene while progressively changing the focus such that for each object of interest, there is at least one image in which it is sharp focus. The images are then combined to create one photo in which all the objects of interest are in focus. In theory, the photos can be taken with any camera that allows manual focus adjustment. Other than the focal depth, all other camera settings must remain the same.
This is the GUI for the Focus Stacking feature:
It is of paramount importance that the camera doesn’t move between the shots; for which reason the use of a tripod is highly recommended.
This engine is very sensitive to camera movement, the camera must remain perfectly still while you are capturing the images.
