What's new, how it compares

All the biggest changes on the EOS-1D X Mark III are on the inside, but there have been some tweaks on the exterior as well. We should note that there's so much to talk about in terms of autofocus that we've devoted the entire next page to covering that in more detail.

Key takeaways:

  • Updated sensor and processor offer better speed and should boost high ISO performance
  • 16 and 20 fps burst rates through viewfinder and in live view (up from 14/16)
  • 20fps burst rate in live view can use either mechanical or electronic shutter
  • New, first-of-its-kind lowpass filter
  • Inclusion of 10-bit HDR stills capture
  • Ergonomic refinements include an AF smart controller
  • Versatile options for 4K capture quality, but limited capture tools

Updated sensor, processor, drive mechanisms and low-pass filter

At the heart of the 1D X Mark III is a 20.1MP full-frame CMOS sensor with Dual Pixel autofocus. It's paired with a new Digic X processor (Canon insists it's pronounced 'ex', and is not a Roman numeral 'ten'). The new processor purportedly offers 3.1x faster image processing and 380x faster computing performance relative to the older Mark II's dual Digic 6+ chips. These improvements bring many new features, primary among them the ability to shoot at up to 20 fps with autofocus and autoexposure in live view with either the mechanical or electronic shutter (16 fps using the OVF). New mirror and shutter drive mechanisms, fine-tuned using simulations, allow for the faster burst rates and reduced viewfinder blackout.

Canon claims the new lowpass filter will result in more naturally blurred backgrounds

Together, the sensor and Digic X processor offer a max native ISO value of 102,400, with a max expanded ISO value of 819,200. These are both one-stop improvements over the 1D X Mark II. We've also been told that users can expect significantly reduced rolling shutter artifacts when using the silent, fully electronic shutter. Our measurements indicate good rolling shutter performance, though it's still no match for the readout speed of Sony's a9 and a9 II sports cameras.

Image courtesy Canon

Sitting in front of the sensor is a newly designed lowpass, or anti-aliasing filter. While these are commonly designed to split light rays to combat the effects of moiré patterning, the 1D X III's is special. Canon calls it a 16-point lowpass filter, which provides separation in eight radial directions. In addition to combatting moiré, Canon also claims that the '16-point separation achieves an MTF pattern that closely matches a Gaussian curve' for more naturally blurred backgrounds greater sharpness for in-focus regions of your images.

HEIF 10-bit HDR photographs

The EOS-1D X Mark III is among the first cameras we've seen that looks beyond 8-bit JPEGs and provides out-of-camera images that more fully exploit the improvements in modern displays and sensors. Modern displays can show a wider range of brightness than used to be possible, meaning you can show a natural-looking view of the world with wider dynamic range.

HDR playback of HEIF files allows for more realistic image viewing on HDR screens.

If you're an iPhone user, chances are you've been taking pictures in the HEIF format already. It's actually more a set of standards than a single file format, and is far more advanced than JPEG, supporting sequences of images, up to 16-bit encoding and wider color gamuts, as well as advanced metadata. HEIF also results in smaller file sizes than 8-bit JPEGs because the compression is more efficient.

Canon's implementation delivers 10-bit files with HDR encoding using the perceptual quanitzer (PQ), a non-linear tone curve designed to encode high dynamic range in a way that's consistent with human vision. It's a standard increasingly widely adopted for HDR content. Furthermore, images are encoded in the wide Rec. 2020 color space, allowing for a wider color palette.

HDR playback allows for a more 'realistic' viewing when you look at images on high dynamic range screens, such as HDR televisions and those in Apple's latest phones. This means that instead of trying to squeeze highlights and shadows into the limited dynamic range of a standard JPEG (which, ironically, can sometimes result in an 'overly-HDR' look), displaying HEIF files on an HDR monitor allows for truly bright brights and dark darks, closer to the contrast we perceive in the real world.

Once you enable HDR PQ shooting, all of your image quality options will change to 'HEIF' instead of 'JPEG.'

Unfortunately, the 1D X Mark III's rear panel is not HDR, but if you shoot in this format, there's a 'view assist' option so the files look more or less normal as you review them in playback, with an option to prioritize accuracy of highlights or midtones.

Canon isn't the first consumer camera manufacturer to offer HDR capture for still images (Panasonic offers stills capture based on the HLG standard), and put simply, there's not a ton of support for these images out there yet. But we're impressed at Canon's forward-thinking by supporting this new format, and we hope to see other companies follow suit.

To encourage its use; if you do choose to shoot in HEIF, you can convert those files in-camera to standard JPEG files if you or your client need them. You can capture them alongside standard Raw and C-Raw files as well (only trying to shoot HEIF + C-Raw risks slowing the camera down).

AF-ON Smart Controller and other operability improvements

The 1D X Mark III comes with what Canon calls the new AF Smart Controller. There are now sensors hidden within the camera's two AF-ON buttons, and as you drag your finger over the buttons - they work almost like very precise touchpads - you can actually control the AF point placement in both the optical viewfinder and Live View. It may sound gimmicky, but it works really well. An EOS R-esque touch bar mis-step, this ain't. Users are given fine control over the Smart Controller's sensitivity in the menus, and it even functions with gloves.

Other welcome additions are a number of backlit buttons on the rear plate which illuminate in tandem with the top LCD info panel. There's also a new, single menu option for a complete factory refresh, and users can magnify the menu interface for easier reading with a two-finger double-tap.


Canon has come out swinging in terms of video on the EOS-1D X Mark III, calling it the 'best movie shooting performance in EOS history'. If you remember back to the original EOS-1D X, you may recall Canon releasing a companion model, the EOS-1D C. It was a video-oriented version of the stills-focused EOS-1D X, with better video features and performance. Thankfully, the EOS-1D X Mark III doesn't need a separate, dedicated 'C' model because it's got some serious video chops built-in.

We've got a full sample reel later in the review, but for now, know that the 1D X III includes the ability to capture 5.5K/60p 12-bit Raw video internally to a CFExpress card. Be aware that a 128GB card only holds around 6 minutes of video at that resolution, so shoot wisely.

Yup, less than six minutes of Raw video on a clear, 128GB card.

For those that don't have a personal server farm to store all that Raw video, the 1D X III also shoots cinema 4K at up to 60p in both All-Intra and IPB formats, though you need to enable a cropped 4K/60p or drop to 30p if you want Dual Pixel AF while shooting - and 10-bit 4:2:2 BT.2020 Canon Log is available in all 4K modes as well, stored in the HEVC format.

DCI 4K footage is oversampled from 5.5K, with UHD 4K oversampled from a slightly smaller crop. In our initial time with the camera, we found video autofocus to be excellent. Unfortunately, you'll have to make do without zebra exposure warnings in any video mode, though you do get focus peaking and Canon's manual focus guide.

For hybrid shooters, it's a breeze to switch back-and-forth from stills to video thanks to the rocker switch on the rear plate, and the fact that the camera now remembers separate exposure settings between the two modes.

CFexpress cards, networking and flash

Gone from the 1D X Mark III are the mis-matched CFast and CF card slots of its predecessor, with a pair of CFexpress slots in their place. CFexpress cards insanely fast, but as with all of the current crop of speedy storage, they cost a pretty penny. But the write speeds they're capable of enable the the 1D X III's almost unlimited continuous shooting, as well as its 5.5K Raw video recording.

Professional users will be pleased to find updated networking options including gigabit ethernet, and Canon has also included built-in GPS and Wi-Fi with Bluetooth. Of particular note is the option for simultaneous communications protocols. This means that you can use an optional external wireless connector (the Canon WFT-E9) to upload files to an FTP service, but use the camera's built-in Wi-Fi and EOS Utility app to operate the camera remotely to adjust settings, as an example.

Flash users will also appreciate new E-TTL exposure options that give more control over the preferred result. These include face priority, as well a new option to bias an image's exposure towards either the flash output or a scene's ambient lighting.

Compared to...

There aren't an abundance of cameras in this class and of this caliber, but the market has seen some newcomers in recent years. In addition to looking at the previous EOS-1D X Mark II and Nikon's D5, we'll look at Sony's a9 Mark II and the Leica SL2, another high-end full-frame mirrorless camera with a deep video feature set.

Canon EOS-1D X III Nikon D5 Sony a9 II Leica SL2 Canon EOS-1D X II
MSRP $6499 $6499 $4500 $5999 $5999
Resolution 20.1MP 21MP 24MP 47MP 20.1MP

Viewfinder (mag, res)

Optical, 0.76x Optical, 0.72x Electronic, 0.78x, 3.68M-dot Electronic, 0.78x,
Optical, 0.76x


2.1M-dot fixed touchscreen 2.36M-dot fixed touchscreen 1.44M-dot tilting touchscreen 2.1M-dot fixed touchscreen 1.62M-dot fixed touchscreen

Image stabilization

Lens only Lens only 5-axis in-body + lens 5-axis in-body + lens Lens only
Burst speed 16fps (20fps Live View) 12fps (14fps Live View) 20fps 20fps 14fps (16fps Live View)
Max video resolution 5.5K/60p Raw 4K/30p 4K/30p 4K/60p 4K/60p motion JPEG
Card format 2x CFExpress 2x XQD /
2x UHS-II SD 2x UHS-II SD 1x CF,
1x CFast
Dimensions 158 x 168 x 83mm 160 x 159 x 92mm 129 x 96 x 76mm 146 x 107 x 42mm 158 x 67 x 83mm
Weight 1440g (51oz) 1415g (50oz) 678g (24oz) 835g (29oz) 1530g (54oz)