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Canon 5D Mark III vs. 1D X
Resolution and High ISO Comparison

© 2014 KenRockwell.com. All rights reserved.

Summary: I'll get into way too much detail below, but all you really need to know is that the 5D Mark III has slightly better technical image quality than the 1 DX, but that the 1D X is tougher and faster than the 5D Mk III.

For 99% of the people reading this, you want the 5D Mk III, not the 1D X.

The 1D X is too big and heavy unless you need its speed or mechanical durability. It's only a good choice for full-time sports and news pros, people who need high frames-per-second for sports, or people shooting in driving rain, sea spray, dirt, dust or blowing sand.

For most people including myself, the 5D Mk III is what I use daily because it's easier to carry and gives slightly better results for things that hold reasonably still, like nature, landscapes, fine art, people, commercial work, studio shots and portraits. The 5D Mk III has slightly higher technical image quality and more resolution and weighs and costs less.

The 1D X is also great for rich people who just like to own nice things, but don't plan to carry it around much. The 5D Mk III is more plasticy, while the 1D X feels and is tougher.

Consider the 1D X as a big, expensive special-purpose professional instrument, and the 5D Mk III as what most people, especially anyone reading this page, really want. If the 1D X was right for you, you'd already know it by now. The 1D X is for sports, or for people who have to shoot in driving rain. Normal people go inside when it starts to rain, while those shooting pro football from down on the field can't.


Intro   Resolution   High ISO   AF   Ergo   Table   Recommendations

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December 2014   Canon Reviews   Canon Lenses   All Reviews

Canon 5D Mark III Review

Canon 1D X Review

2012 DSLR Comparison

To compare to Nikon D4, D800, D1, D3 (D700), D7000 and Canon 5D, 5D Mark II, and Fuji X-Pro1 and X100, see High-ISO Comparisons of the Nikon D1, D3 (D700), D4, D800, D7000 and Canon 5D, 5D Mark II, 5D Mark III and Fuji X-Pro1 and X100 which includes the same 5D Mark III compared here. The 1D X isn't on that page, so look at its performance relative to the 5D Mark III and interpret accordingly. Note that this page uses my Picture Style settings which are the same between Canons, but the other, larger comparison I set all the cameras back to neutral settings, so don't compare images from the two pages directly: compare them relatively.


Canon 1D X review

Canon 1D X: 18 MP full-frame, 53.8 oz./1,526g 12 FPS, $6,800.


Canon 5D Mark III

Canon 5D Mark III: 22 MP Full-frame, 33.7 oz./956g, 6 FPS, $3,500.


Introduction         top

Intro   Resolution   High ISO   AF   Ergo   Table   Recommendations

Let's compare the sharpness of Canon's two top cameras of 2012: the 22MP 5D Mark III versus the 18 MP Canon 1D X.

Honestly, after owning both of these for a short while, it's apparent that each is the same camera inside as far as technical image quality and software are concerned. Canon developed both of them at the same time, and the software and firmware are the same with very little difference. The mechanics of the bodies are different, with the 1D X having a big, tough body with big motors to run fast, while the 5D Mark III is the same thing in a much more reasonable package. The sensors are slightly different for marketing purposes, and as you'll seen the 5D Mark III is a little better, but not by much. The AF systems are astoundingly the same!

These are crops taken from the center of these images, each shot with the Canon EF 50mm f/1.8 II USM at ISO 100 and f/5.6.

On most computer monitors at 100 DPI, these are small sections from what would be gallery-sized 55" x 33 " (4.5 x 3 feet, or 1.5 x 1 meters) prints, if printed in their entirety. Few people, if anyone, prints this big. At smaller sizes, these differences will be even less obvious.

In all cases, these are presented at the same print size.

In the first section, I slightly enlarged the smaller 18MP 1D X image to the same size as the 5D Mark III image. Each camera was set to 6 sharpening, and + 3 for saturation, as I usually shoot.

In the second section, I reduced the 5D Mark III image to the same size as the 1D X image. In each case, it was a simple integral 9/10 or 10/9 magnification.

You may click any image to get to that camera's detailed review.


Resolution at 22MP    Intro   Resolution   High ISO   AF   Ergo   Table   Recommendations

Canon 5D Mark III Review Canon 1D X Review

For those of you with mice and computers, here are larger crops from the same files presented so you may roll your mouse over to compare:


For those who think that the 1D X looks softer because it was unfairly enlarged to the same print size, which is exactly what happens when you print these the same size (duh), here is the same comparison, instead reducing the 5D Mark III's image down to the 18MP of the 1D X, and again, printing them the same size, but this time with the 1D X image left as-is:


Resolution at 18MP    Intro   Resolution   High ISO   AF   Ergo   Table   Recommendations

Canon 5D Mark III Review Canon 1D X Review

For those of you with mice and computers, here are larger crops from the same files presented so you may roll your mouse over to compare:


As expected, the sharpness difference remains.

No surprises: 18MP versus 22MP is a 10% difference in linear resolution, and that's what we're seeing. The 5D Mark III remains its sharpness advantage even at smaller sizes because digital camera makers lie; they use Bayer interpolation from filtered black-and-white image sensors, so the real resolution is only about one-half of what Nikon or Canon or LEICA or anyone else claim. (Sigma lies in a different way; their resolution is only about one-third what they claim.) Therefore, even when reduced, the higher-resolution camera usually wins, as it does here.


High ISO    Intro   Resolution   High ISO   AF   Ergo   Table   Recommendations

Consumer warning

My 5D Mark III is about a half-stop faster at any given ISO setting than my 1D X.

In other words, at any given ISO, my 5D Mark III gives the same image with a half-stop less exposure. In other other words, my 5D Mark III actually runs at a half-stop higher ISO than marked, or my 1D X is actually running a half-stop slower than marked, or somewhere in between.

It's common for camera makers to cheat a little here, since Canon needs to make the 1D X look like it has better high ISO performance than the 5D Mark III. In this case, it's stacked the deck a little, since when anyone compares at the same indicated ISOs, the 1D X appear to have a half-stop advantage since it's really only operating at a half-stop less ISO than the 5D Mark III at any given ISO. When comparing images, you won't notice unless you shoot at the same manual exposure, in which case my 1D X is a little darker than my 5D Mark III, or if you get both to match, you'll notice that your 5D Mark III only needed about a half-stop less exposure.

In these samples below, each is taken from crops from 100% images and the indicated ISO settings were the same as shown. All were shot at f/5.6 in manual exposure, however the shutter speeds were one-third stop faster on my 5D Mark III to get the exposures to match!

Canon 5D Mark III Review Canon 1D X Review
Canon 5D Mark III Review Canon 1D X Review
Canon 5D Mark III Review Canon 1D X Review
Canon 5D Mark III Review Canon 1D X Review
Canon 5D Mark III Review Canon 1D X Review
Canon 5D Mark III Review Canon 1D X Review
Canon 5D Mark III Review Canon 1D X Review
Canon 5D Mark III Review Canon 1D X Review


Whew! Regardless of which is better or worse, there isn't much difference from camera to camera when compared to one ISO or another. All cameras look really crappy at crazy-high ISOs compared to low ISOs. All cameras apply varying degrees of noise reduction, and as you can see, smooth-away most of the detail in the process. Hyper ISOs can look clean, but much softer compared to low ISOs.

Which really is better, since the 1DX is cheating by about a half stop?

Let's even the tables a bit, and resize the 5D Mark III down to the same size as the 1D X, and let's see what happens at similar exposures:

5D Mark III @ 1/3,200s
1D X @ 1/4,000s
Canon 5D Mark III Review Canon 1D X Review

At this ISO, the two cameras were about a half-stop different in their marked sensitivities. At 1/3,200 at ISO 102,400 the 5D Mark III was a little darker than the 1D X at ISO 204,000 at 1/4,000. I pushed the 5D Mark III a third of a stop in Photoshop 6 to get the two to match here.

Now that we're comparing more evenly, they are about the same. Both look about as crappy at this speed. The 1D X has a hot pixel (the red dot) and more grain, but the extra grain in the 1D X makes it look sharper, even if neither image has any fine detail.

Autofocus         top

Intro   Resolution   High ISO   AF   Ergo   Table   Recommendations

See also my 2012 DSLR Comparison.

Each has ONE SHOT and AI SERVO AF Modes. The 5D Mark III adds AI FOCUS, which selects either of the other two automatically.

I kid you not, but owning both of them and comparing them in the same conditions side-by-side with the same lens, each is as fast in good light, and each is slower, but still about as fast as the other, in very dim light.

I'll be honest: in crappy light too dark to read a book, neither focuses that well. Turn on some light! In dim light where it matters, each is the same, with maybe the 5D Mark III working a little better — when just one sensor is selected.

If you're seeing differences, it's because you don't have them right there with you at the same time and the potent powers of suggestion are making you think the big pro camera must be faster, or more likely, you don't have them set exactly the same. AF performance varies with different settings, but set them the same, and my 5D Mark III and 1D X work the same in dim light or daylight, with crappy plastic toy lenses or professional L lenses. Canon knows the AF systems are so complex that you'll never be able to set both the same way, and when you've got the 1D X working faster than the 5D Mark III, you'll believe it. Strange, but true; they use the same technology, except:

The 1D X excels if you use the iTR mode that lets the 1D X use the same technology Nikon does in the D3, D700, D4 and D800 to use color and face recognition and depth to let the AF areas track targets moving around the finder. The 5D Mark III lacks this technology, and is much worse than the rest of these at tracking things around the finder as the subject moves or as you recompose.

If you want to select a point and let the camera track it well, you need the 1D X (or a Nikon). While the 5D Mark III offers a left-right-up-down tracking mode, it usually loses your target quite easily, while the 1D X and the Nikons stay right on it.

If you waste your time counting AF points, here's how Canon specifies them:

AF Points
Cross-type @ f/2.8
Cross-type @ f/4
Cross-type @ f/5.6
AF Modes







Ergonomics         top

Intro   Resolution   High ISO   AF   Ergo   Table   Recommendations

See also my 2012 DSLR Comparison.


The 1D X is built tough out of all metal, while the consumer 5D Mark III has plenty of plastic, especially on its flimsy mode dial.


Light Meter

Each works about as well as the other in practice. Neither is perfect.

The 1D X merely has more digits in its specifications, but the ultimate smarts behind each is the same.

Light Meter
Full RGB
two-color only


Sound and Noise

In their normal single-shot modes, the 5D Mark III is quieter. This makes sense; the 5D Mark III is running at half the speed.

In its "Silent" mode, the 1D X is significantly louder than the 5D Mark III is in its "Silent" mode. The 5D Mark III's Silent mode is smooth and quiet, while the 1D X' Silent mode is still noisy.

In fact, the 1D X' silent mode disconnects the shutter cycle into two noises, taking and then flipping down the mirror, either of which is much louder than the 5D Mark III's complete Silent shutter shot.

The 5D Mark III's Silent mode works at once, while the 1D X's Silent mode is two noises, one for the beginning of the shot, and another noise when you let go the shutter. The 1D X' finder is BLACK until you remove your finger, while the 5D Mark III works normally in its Silent mode.

The 5D Mark III in its normal mode is about as loud as each half of the 1D X' disjointed "Silent" Mode.

If you need quiet, forget the 1D X and get a spare 5D Mark III for your more sensitive gigs; it's like night and day — and the 5D Mark III is much faster in Silent mode than the 1D X is in its noisy "Silent" mode.



The finder size is about the same, with the 1D X having a few percent more image size and the 5D Mark III having slightly more eye relief.

The ratings are:

Changeable Screens?
Shows Exposure Modes?
Apparent Angle
Eye relief


The data displayed at the bottom is the same size and weight.

The 1D X adds exposure mode (as well as C1, C2 and C3) indications, as well as has its bar graph running vertically along the right, and shows both flash and ambient exposure compensation at the same time.

Both use the same screen with the same AF point indicators and illumination. Each has about the same eye relief.

The 1D X adds a perplexing [ AF ] symbol over the lower left of the image. I have no idea what it means.

The 1D X can accept special interchangeable screens for better manual focusing with fast lenses, while the 5D Mark III's screen is now fixed. (The 5D and 5D Mark II has interchangeable screens, but not the 5D Mark III.)


Manual Preset White Balances

These are a pain to set in the 5D Mark III, requiring menu foolishness.

The 1D X offers a faster way to set this, as well as five memory positions. (The 5D Mark III can use only the one current setting.)


Multi Spot Metering

The 1D X offers this, with up to 8 points (page 174), while the 5D Mark III does not.

Canon introduced this on the T90 of 1986. I've never used it.



The 5D Mark III's top LCD is much easier to read, with bigger everything.

The 1D X' top LCD makes everything too small to read.

The 5D Mark III's top LCD illuminator button is right under your finger so you can hit it while shooting one-handedly; while the 1D X hides the top LCD illuminator way inboard where you need a second hand to hit it.

The 5D Mark III lights up in easy-to-read amber, while the 1D X lights in much more difficult to read red-orange.


Rear LCD Monitor

Each has the same best-in-the-world read LCD, better than anything ever from Nikon.

Oddly, the 5D Mark III has an excellent AUTO brightness control option, which the 1D X lacks.


Voice Notes

Mandatory for a pro camera for note-taking, the 1D X has a direct voice notes button, while the 5D Mark III is clueless.


Playback Speed

When zoomed on playback, the scroll speed when you hold or move the little thumb nubbin is identical between these two cameras.

When scrolled, the image stays blurry for the same amount of time in each camera before sharpening up a moment later. This is a core incompetency of Canon; I'm amused that the 1D X isn't any better here than the first 3MP 1.6x Canon D30 that came out in April, 2000, twelve years before this 1D X.



Save settings to card?
JPG compression settings
Live View
Can you disable LV so it won't turn on accidentally and run down the battery?

Note how the 1D X is a serius camera, and therefore skips the HDR baloney, but adds the ability to save complete camera setups.


Comparison Table         top

Intro   Resolution   High ISO   Comparison Table   Recommendations


See my 2012 DSLR Comparison.


Recommendations         top

Intro   Resolution   High ISO   Comparison Table   Recommendations

Our choices are easy:


Image Quality

The 5D Mark III has a slight advantage. It has slightly more resolution, and about the same hyper ISO performance when compared at the same exposures (the marked ISOs are off by about half a stop, making the 5D Mark III look a little worse until you correct for the difference in actual sensitivity between cameras).

I didn't compare with the same exposures above; I compared at the same marked ISOs, which are about a half stop off in favor of the 1D X. If I did even more work to shoot at the same exposures, they would be closer.


News, Sports and Action

The 1D X has a huge advantage not tested on this page, but it runs twice as fast at everything.

AF is about as fast, however the 1D X adds color and motion to its AF-area tracking ability, which is a huge help in every live-action shooting situation, be it snapping my kids or shooting the Olympics.

Of course its frame rate and metering and everything else just crank faster. The 5D Mark III is fast, and the 1DX is twice as fast.


Inclement Weather

Also not tested on this page, but if you shoot in rain and mud and dust, the 1D X again has a huge advantage.

I haven't beat on either of mine yet, but as other pro friends explain, even though they don't need the speed, they'll be snapping in the streets of Thailand, and if it starts to rain, they just keep shooting as things get interesting. The weather gets nastier, but they ignore it and focus on their pictures, not their cameras.

A half-hour later when they step under an overhang to catch their breath, they realize that they are as wet in this monsoon as if they fell overboard. No problems, their pro Canons just keep on working.

Others with 5D Mark IIs who were following them trying to copy what they were doing discover that they were not so lucky: drenched consumer cameras like the 5D Mark II or Mark III, are all dead.

I don't shoot in the muck, but if you do, you can be fearless with pro gear like the 1D X. That's why you use the 1D X: to get the shots consumers can't.


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Thanks for reading!



Mr. & Mrs. Ken Rockwell, Ryan and Katie.


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July 2012