Canon EOS-1D X Mark III

EF mountDSLRFull frame

Can FoCal calibrate my EOS-1D X Mark III?

Yes: FoCal finds the best AF Microadjustment value for each lens.

The EOS-1D X Mark III doesn’t let FoCal change AF Microadjustment over USB, so FoCal tells you the value to set on the camera when it needs it (User Assisted Mode), with separate wide and telephoto values for zoom lenses.

And FoCal can check the rest of your kit.

Supported in FoCal 2.13 and later, over USB-C or Wi-Fi. Tests: Calibration Check, AF Consistency, Aperture Sharpness, MultiTest, Stabilisation Test and Dust Analysis.

75.9%

Tuning an EOS-1D X Mark III would improve almost 8 out of 10 lenses.

And 44% would improve significantly. From calibration results FoCal users have shared with FoCal IQ.

From FoCal IQ: see the figures

Significant44%

Noticeable31.9%

Minimal15.3%

Bought it second-hand?

You don’t know how a used EOS-1D X Mark III has been treated. Cameras and lenses get knocked, drift and wear, usually gradually. FoCal shows you where yours stands.

Calibrate it with your lenses
Any AF Microadjustment values already on the camera were set by someone else, for their lenses. FoCal finds the right value for each of yours.
See how it performs
AF Consistency shows how repeatable the autofocus is, and Aperture Sharpness how sharp each lens is across its apertures.
Look at the sensor
Dust Analysis counts the dust spots and shows how much they matter, before you pay for a clean.
Then keep an eye on it
With FoCal Pro, a regular Kit Health Check tracks every result, so you’ll see if anything changes.

About the Kit Health Check

What you can do

Seven tests for the EOS-1D X Mark III

Focus Calibration

Finds the best AF Microadjustment value for each lens. The camera won’t let FoCal set it over USB, so you change it when FoCal asks.

Available

Calibration Check

A one-click check of your EOS-1D X Mark III and lens. In a minute or so it shows whether your kit is working as it should.

Available

AF Consistency

How repeatable is the EOS-1D X Mark III’s autofocus? Defocus between shots in one or both directions and see.

Available

Aperture Sharpness

What happens to sharpness as you change aperture, and which aperture is the sharpest.

Available

MultiTest

A two-dimensional view of the lens: focus position across the aperture range, showing any focus shift.

Available

Stabilisation Test

How much does stabilisation really help? See the quality change as the shutter speed slows.

Available

Dust Analysis

Count the dust spots on the sensor and see how much they matter, before you decide on a clean.

Available

Snapshots

This feature is not yet available for the EOS-1D X Mark III.

Not available

Calibration Check (AF System Check) is free in FoCal Mobile.

FoCal IQ statistics

Tuning an EOS-1D X Mark III would improve almost 8 out of 10 lenses

From calibration results FoCal users have shared with FoCal IQ: how far each EOS-1D X Mark III and lens was from the best AF Microadjustment value before FoCal tuned it.

EOS-1D X Mark III with EF-mount lenses

75.9%

of lenses would benefit noticeably from FoCal calibration, and 44% would improve significantly.

Significant44%

Noticeable31.9%

Minimal15.3%

Source: FoCal IQ: EOS-1D X Mark III (EF mount), 1,006 results.

Significant: 4 or more AF Microadjustment units. Noticeable: 2 or 3 units. Minimal: no more than 1 unit.

Why your EOS-1D X Mark III needs it · an illustrated guideYour DSLR doesn’t measure focus where it takes the pictureHow a DSLR focuses, what goes wrong, how to fix it, and the evidence from FoCal users.Read the guide

How to set it up

Setting up your EOS-1D X Mark III for FoCal

Connecting the cameraUSB-C or Wi-Fi

Use a good USB-C cable
FoCal controls the EOS-1D X Mark III over USB. Use the cable that came with the camera or a good-quality one, and avoid extension cables: a poor cable is the first thing we suggest changing if FoCal is unreliable.
Or connect over Wi-Fi
FoCal can also use the EOS-1D X Mark III’s Wi-Fi. Turn on the Wi-Fi option for Canon in FoCal’s settings first, then see Connecting over Wi-Fi.

Permissions on macOSfirst connection

When you first connect, allow access to the Photos Library and to Removable Media. FoCal needs both to talk to the camera.

If a permission shows as Denied
In FoCal, open Help then Settings, expand Advanced and click Reset Application Permissions. Restart FoCal and it will ask again.

Connecting over Wi-FiCanon Wi-Fi

First: turn on the Canon Wi-Fi option in FoCal (Help › Settings, General tab), or FoCal won’t find the camera.

The camera side is in Canon’s EOS-1D X Mark III network guide.

More on hotspot (“easy”) and infrastructure connections in the camera network help.

AF Microadjustment on the EOS-1D X Mark IIIwhere to find it

Open AF Microadjustment
Press MENU and go to the AF 5 tab. Select AF Microadjustment and press SET.
Choose “Adjust by lens”
FoCal sets a value for each lens, so select Adjust by lens, then press INFO.
Set the value
For a prime lens, change the value on the screen.
For a zoom lens, select W (wide) or T (telephoto), as FoCal asks, and press SET. Then change the value with the rear dial.
Save it
Press SET to save the value, then MENU to go back. The values you chose are shown.
Tell FoCal you’re done
Use the camera hotkey: see User Assisted Mode.

About User Assisted Modechanging the value

FoCal controls almost every setting it needs on the EOS-1D X Mark III, but the camera doesn’t let it change AF Microadjustment over USB. During calibration or MultiTest, FoCal asks you to change it a few times.

FoCal asking for the AF adjustment value to be changed on the camera

Listen for the value
While FoCal’s request is on screen, the camera controls work. Voice prompts are on to start with, so your computer reads out the change you need.
Change it on the camera
Press MENU to open the menu, SET to select AF Microadjustment and INFO to change it. Set the value and press SET.
The menu remembers where you were, so after the first time it’s quick.
Use the camera hotkey
Half-press the shutter button to go back to shooting, then turn the aperture or shutter speed dial by one click. FoCal sees the change, waits a moment for the camera to settle, puts the setting back and carries on.

Your test space5 steps

Choose a solid floor
Ground-floor rooms vibrate less when people move about or traffic passes, and vibration affects the results.
Fix the target to a wall at lens height
Keep it flat so it can’t move. A FoCal Hard Target is what we use for all our development and testing.
Light it well and steadily
Avoid fluorescent and LED lights, which can flicker in a way you can’t see but the camera can, and changeable daylight. FoCal copes with small changes in light, not big ones.
Use a sturdy tripod
If your tripod has a hook under the centre column, hang something heavy from it. With big lenses, mount the lens’s tripod collar, not the camera.
Set the right distance
The Target Distance Tool in FoCal tells you how far from the target to be, with or without the camera connected.

Target Setup, FoCal’s guided setup, checks the position, light and settings before a test. More in the FoCal help.

Camera set-up4 steps

Charge the battery to at least half
Low batteries can make tests fail or the camera behave strangely.
Take off any battery grip
Grips add vibration on a tripod.
Aim the centre focus point at the target
Roughly is fine: Target Setup confirms the position.
Cover the eyepiece
This stops stray light getting in through the viewfinder and changing the exposure.

Camera settings8 steps

Photo mode
If the EOS-1D X Mark III has a photo/video switch, set it to Photo.
Wi-Fi off for USB
If you’re connecting by USB, turn the EOS-1D X Mark III’s Wi-Fi off: it can interfere.
Remove any mode limits
If the camera lets you limit its options, allow Aperture Priority and Manual, Spot and Matrix/Evaluative metering, and all apertures, shutter speeds and ISO values.
Aperture Priority
Most FoCal tests use it. FoCal asks if a test needs something else.
One Shot autofocus
Set the autofocus mode to One Shot: a half-press of the shutter button locks focus and then stops.
A single, centre focus point
No automatic point selection: you should see one fixed AF point, in the centre.
Focus limiter off
FoCal may use the lens’s whole focus range, so set any focus limiter on the lens to off or the full range.
Stabilisation off
Turn off any stabilisation on the lens: it can make the results less accurate.

Specifications