Focus stacking

The English term focus stacking, literal translation " focus stack", rarely also depth of field extension or deep focus fusion ( DFF ) called, describes a combination of photographic recording and digital image processing technology. It is used in particular in the digital macro photography to produce an image with exceptionally large depth of field. In metrology, this technology is also called focus variation.

Method

Similar Exposure Blending Focus stacking is the combination of a photographic shooting and a subsequent assembly process. However, in this case the Series is no bracketing, but an image sequence, in which only the focus was changed so that the images differ only in the focus position.

As can result in a change in the magnification in the focus change and objects can move slightly in the image, an image transformation to best overlay of the images must be prior to the actual assembly of the individual images are usually carried out yet. This object is achieved by the special programs automatically.

In the subsequent assembly then each sharpest areas of the images are merged. The fast Fourier transform is used by the special programs.

Software

Since the manual assembly of the images is difficult and time consuming, use is made in general to special software:

  • Adobe Photoshop (automatic stacking since CS4, commercial, Windows / Mac OS X)
  • Helicon Focus (commercial, Windows / Mac OS X)
  • ProgRes CapturePro (commercial, Windows / Mac OS X, included a ProgRes camera)
  • Combine ZM or its newer version Combine ZP (Open Source, Windows)
  • Enfuse (Open Source, Linux / Windows / Mac OS X)
  • Macro Fusion ( Open Source, Linux, GUI for Enfuse )
  • Deep Focus Module for Quick Photo software (commercial, Windows)
  • ZereneStacker (commercial, Linux / Windows / Mac OS X)

Example ( dental bridge ):

Figure 2 (focus point in this and the following images always something further to the rear)

Picture 3

Picture 4

Picture 5

Picture 6

Figure 7 (focus point in the back )

Result of the Focus stacking with Combine ZP ( Macro: soft stack; Version: 2012)

Image editing
225188
de