Focus stacking

Series of images demonstrating a six-image focus bracket of a Tachinid fly. First two images illustrate typical DOF of a single image at f/10 while the third image is the composite of six images.
Focus stacking (for extended depth of field) in bright field light microscopy. This example is of a diatom microfossil in diatomaceous earth. Three source images at different focus distances (top left) are combined with masks (top right) to obtain the contributions of their respective images to the final focus stacked image (bottom). Black is no contribution; white is full.

Focus stacking – also called focal plane merging, z-stacking,[1] or focus blending – is a digital image processing technique which combines multiple images taken at different focus distances to give a resulting image with a greater depth of field (DOF) than any of the individual source images.[2][3] Focus stacking can be used in any situation where individual images have a very shallow depth of field; macro photography and optical microscopy are two typical examples. Focus stacking can also be useful in landscape photography.

Focus stacking offers flexibility: since it is a computational technique, images with several different depths of field can be generated in post-processing and compared for best artistic merit or scientific clarity. Focus stacking also allows generation of images physically impossible with normal imaging equipment; images with nonplanar focus regions can be generated. Alternative techniques for generating images with increased or flexible depth of field include wavefront coding, light-field cameras and tilt.

  1. ^ "Malin Space Science Systems - Mars Science Laboratory (MSL) Mars Hand Lens Imager (MAHLI) Instrument Description". Msss.com. Retrieved 2012-12-10.
  2. ^ Johnson, Dave (2008). How to Do Everything: Digital Camera (5th ed.). McGraw-Hill Osborne Media. p. 336. ISBN 978-0-07-149580-6. There are a number of programs that allow you to get the equivalent of infinite depth of field in your photos, with sharp focus from the foreground all the way back to the rear. How is this possible? By taking multiple photos of the same scene and stacking them afterwards into a composite that features only the sharpest bits of each image. One of the best is Helicon Focus.
  3. ^ Ray 2002, 231–232