How it works

Four steps to a calibrated lens.

FoCal takes control of your camera and does the hard work. Your part is a tripod, a target on the wall and a cable to your computer.

  1. 1

    Connect

    Camera on a tripod, the FoCal target on a wall, and a USB cable to your Windows PC or Mac. FoCal takes control of the camera.

  2. 2

    Check the setup

    Target Setup checks the camera position, distance, light, camera and lens settings and battery, and tells you what to change.

  3. 3

    Calibrate

    Choose Focus Calibration and press Start. FoCal takes and measures the shots and works out the best autofocus adjustment by itself.

  4. 4

    Sharper shots

    See the before and after, and the setting FoCal chose. The camera keeps it for that lens from then on.

Step 2 · Target Setup

Confidence in the result before you start.

Accurate results need a good setup, but you don’t need a checklist: Target Setup checks it for you, with live view from the camera so you can line up the target.

  • Target placement and distance, with the recommended distance for your focal length
  • Lens and camera settings, and FoCal’s own settings
  • Light level and battery

Each check shows green, or tells you what to change and why.

FoCal 6 Target Setup with a Nikon D850: live view of the target, and the environment checks, some green and some with advice.
Target Setup running: green checks, and advice on distance, focal length and light.
FoCal 6 Target Setup before starting: the list of checks it will run and the recommended target distance.
Before you start: the checks Target Setup will run, and the recommended minimum target distance.
Step 3 · Fully Auto calibration

FoCal finds the sharpest setting, by itself.

FoCal sets the camera up, changes the autofocus adjustment, focuses and takes shots at each setting, downloads and measures them, and homes in on the value that gives the sharpest result. You can watch the lens profile build up as it goes.

On zoom lenses, cameras that store separate wide and tele values get both.

FoCal 6 calibration result for a Nikon D850 and 50mm f/1.4: the lens profile chart from −20 to +20 with the best value at −12, and before and after crops of the target.
The lens profile: sharpness at each AF Fine-Tune value, and the best one FoCal chose.

When the camera won’t let FoCal change the setting

Some cameras, including all Nikon bodies and some Canon ones, don’t let software change the adjustment. FoCal still does the measuring and works out the value; it just asks you to set it in the camera’s menu, then carries on when you press Continue. Your camera page says which way your camera works, and where the setting is.

FoCal 6 AF Fine-Tune Change Request: the camera can’t be changed automatically, so FoCal asks you to set the telephoto AF Fine-Tune to −20, then press Continue or the Camera HotKey.
FoCal shows you the values to set.
Step 4 · The result

See the difference.

At the end, FoCal shows the value it worked out and the target before and after, side by side, with the quality of focus for each. Accept it to keep the new value, or reject it to put the old one back.

With FoCal Pro, the Compare tab shows how your result sits against other FoCal users with the same camera and lens, and every result goes into your History for the Kit Health Check.

FoCal 6 Focus Calibration Result: AF Fine-Tune −15, with before and after crops of the target and quality of focus rising from 1329 to 1701, and Reject and Accept buttons.
The calibration result: before and after, then accept or reject.
Calibration Check

A quick check between Kit Health Checks.

CalCheck compares how well your autofocus is doing now with the best FoCal can find, with no input from you, and tells you whether it’s worth calibrating.

Use it when there’s no time to set up for everything, for example before a shoot. It also works on tethered cameras that have no autofocus adjustment, so you can see whether things are working as they should.

Once you’re set up for a full check, calibrate instead: CalCheck isn’t much quicker and tells you much less.

FoCal 6 Calibration Check result for a Nikon D850: autofocus performance below the best, 'Worth Checking', with Excellent result confidence and crops comparing measured and best focus.
CalCheck: this lens is worth calibrating.

Step-by-step instructions are in the Fully Auto guide, the CalCheck guide and the FoCal help. You’ll need the FoCal target: buy the Hard Targets, or print it yourself from the target images.

See what your lenses can really do.

Check FoCal supports your camera, then pick the edition that fits how you shoot.

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