Target Distance Tool: AutoFocus Calibration

You can use the Target Distance Tool to suggest a suitable target distance for AFMA / Focus Fine Tune lens calibration with Reikan FoCal.

Note: this functionality is now part of FoCal, scroll down to read about the new feature!

Choose camera, lens focal length and target size:

Lens Focal Length
Target Size



Target Distance Tool Now in FoCal

Starting from FoCal 2.5 the target distance tool is now part of FoCal software.

Auto focus calibration distance

Users can select a focal length by selecting “Specify focal length” and moving the slider:

AF target calibration distance

When a camera is connected to FoCal the top option is selected by default and FoCal reads the lens information automatically. With zoom lenses both ‘ends’ of the zoom will provide a distance (see also calibrating zoom lenses):

focus calibration zoom distance

Choose between Feet and Inches or metric via Preferences > Tests:

focus calibration feet and inches


More Information

The document What’s the correct distance to run tests at? contains further useful information and explains why target distance is important and why the distance used does not need to be precisely measured in most cases.