User Assisted Mode

FoCal runs on your computer and connects to the camera using a USB cable (supplied in the box with new cameras). Using this connection it is able to operate the camera remotely, driving it to capture test images, download those images and analyse them for sharpness to determine the best AF calibration value for each lens. A series of proprietary image processing and predictive statistical algorithms mean that FoCal is able to calculate the best AF calibration for a particular lens accurately and easily, with minimal input from the user.

Software control of the AF Micro Adjustment (or AF Fine Tune) setting on certain cameras (designated as "User Assisted") is not possible from a computer. The features that can be controlled are dictated by the camera manufacturer, they expose the ability to adjust certain settings through a documented interface which FoCal uses to make all the necessary automated adjustments to the camera.

What this means is that FoCal still provides its full automated calibration, determining which and how many AF Fine Tune points are needed for the calibration result. Other things, like setting mirror lockup and de-focusing between each shot, analysis of each image for sharpness/detail and graphs to determine the best AF calibration value work automatically. During the calibration process, a number of AF Fine Tune changes need to be set on the camera and they have to be input by the user as directed by FoCal (so it's "user assisted" in that sense).

We continue to try to get the camera manufacturers to add this software functionality and we've got some ideas on how to go about this so it's not a done deal(!). In the shorter term we've worked on making the "user assisted" part of the process easier, fewer AF Fine Tune steps required and "Voice Prompt" along with the camera HotKey mean the process is very quick and simple.

Watch a full overview of FoCal Pro running an automated calibration at YouTube: FoCal "User Assisted Mode" Calibration

Hands Free Mode

FoCal runs on your computer and connects to the camera using a USB cable (supplied in the box with new cameras). Using this connection it is able to operate the camera remotely, driving it to capture test images, download those images and analyse them for sharpness to determine the best AF calibration value for each lens. A series of proprietary image processing and predictive statistical algorithms mean that FoCal is able to calculate the best AF calibration for a particular lens accurately and easily, with minimal input from the user.

This mode works in a very similar way to User Assisted Mode, with FoCal able to make settings changes on the camera automatically. The difference with this mode is that FoCal is also able to automatically change the AF Micro Adjustment / AF Fine Tune setting. Once a FoCal calibration is running the user does not need to input any values and FoCal runs "Hands Free".

Watch a full overview of FoCal Pro running an automated calibration at YouTube: FoCal "Hands Free Mode" Calibration

Wide/Tele Zoom Calibration

A single calibration will produce a focus adjustment result that is useful for a single focal length of a lens.

With the release of the EOS 5D Mark III back in 2012, Canon enabled Wide and Telephoto Calibration for zoom lenses. This allows you to set a focus calibration value for both the wide and telephoto ends of the focal range, and the camera will intelligently determine the actual value to use depending on the selected focal length.

Nikon followed suit by introducing this feature in the D780 in January 2020, and has since added to more cameras.

Analysis Only Cameras (No Focus Adjustment)

Although FoCal was initially developed to calibrate autofocus on cameras that support microadjustment/fine tuning, there are also a number of other useful features that are available to cameras which do not support this capability: for example measuring the sharpness across the aperture range with the Aperture Sharpness test; quantifying dust on the sensor with the Dust Analysis test etc.

Where possible, we automate this functionality to make it easy to use, so if the camera is listed above in the tables as Analysis Only it means that the camera is automatically controlled for all supported analysis tests, but it does not offer the capability to calibrate autofocus.

Beta Camera Support

We run an extensive suite of validation tests against cameras before we release tethered support so FoCal can automatically control the cameras. However, it's unrealistic to have access to the ever-increasing range of cameras supported by FoCal, so we tend to have one or two models from each range (e.g. usually the same internal processor) of cameras that behave similarly.

Where there are other cameras in the range that we don't have access to but are confident that FoCal will work as expected, we enable these in Beta mode. This means that the cameras should work as expected with FoCal.

See the Beta Camera Support section of th eonline help for more information.

Not Supported by FoCal (Sony / Pentax / Panasonic etc)

FoCal's support for a wider range of cameras is something we continue to investigate. Both Nikon and Canon make available a software library that FoCal uses to control these cameras. This type of software control is slowly starting to become possible for other cameras and when it does you can be sure we will be looking to extend FoCal to accommodate them.