Focus stacking

Focus stacking is a digital photography technique, which combines multiple images taken at different focus distances. It can be used in any situation where individual images have a very shallow depth of field; for instance macro photography.

DK uses this technique to ensure front to back focus for much of our object photography.

A series of images are captured at different focal depths; in each image, different areas will be in focus. None of the images will be entirely in focus, but collectively they contain all the information needed to create an image which is. These are combined to give a resulting image with a greater depth of field than any of the individual source images.

The images are combined automatically using focus stacking software (Photoshop, Helicon focus, and Zerene stacker are 3 of the most common)

Due to the automated process, and limitations of the software, care must be taken with each individual image to ensure no problems with the stacking.

You will need to check the images you receive after a shoot for the following potential issues.

Alignment issues

This is caused when the camera or subject moves slightly. Shooting living things, such as flowers, or insects can cause these problems. Even in a studio environment, the slightest movement will cause problems.

Blurring

Some subjects with larger depths or complicated overlapping areas can confuse the software leaving blurred areas.

All images should be supplied ready to use, with no problems.
In any of the above cases a discussion should take place with the person performing the stacking to find a solution.
Sometimes the problems can be retouched out or a new stack should be made taking care to avoid the same issues.