Canon EOS 5D MkIII Hands-on Review

On March 2nd 2012 Canon announced the canon_5D3-body as an upgrade of – but not a replacement for – the EOS 5D MkII. Among the major new features of the EOS 5D MkIII are:

  • A new 22.3MP CMOS sensor with a gapless microlens, 8 channel readout and low noise
  • A new 61 point AF system with 41 cross sensors (same as EOS 1D X) with AF to -2EV
  • A 63 Zone iFCL metering (same as EOS 7D)
  • Native ISO settings of 100-25600 with expansion to 50-102400
  • A new Digic 5+ processor (30% faster than Digic 5, 17x faster than Digic 4)
  • 6fps continuous shooting
  • In-camera HDR. 3 images taken at +/- 3 stop intervals with in-camera image alignment

Currently (July 2012), the EOS 5D MkIII sells for around $3450 and the EOS 5D MkII sells for around $2100

There were a host of other features that were upgraded or added, but the new sensor, new AF system and new processor are the major advances which enable many of the other upgrades such as faster shooting (6 fps vs 3.9 fps) and more extensive in-camera processing. With a processor 17x faster than that in the EOS 5D MkII, real time chromatic aberration correction is now available for JPEGs, and in video modes the extra processing power enables better moire fringing correction.


Outwardly the EOS 5D MkIII resembles the EOS 5D MkII quite closely, but the user interface is closer to that found on the Canon EOS 7D, with a similar menu structure and control layout. In common with all of Canon’s full frame DSLRs, the 5D MkIII does not have a built in flash (which the EOS 7D does). In some ways the 5D MkIII is as much of an updated full frame version of the EOS 7D as it is a direct update of the EOS 5D MkII, since it incorporates many features found on the 7D, such as electronic levels for example.

Also very important is the new AF system. While the 5D MkII inherited its 9-point AF system from the original EOS 5D (which can trace its AF origin back to the EOS 20D and 30D), the 5D MkIII shares its AF system with Canon’s brand new flagship EOS-1D X. It now has 61 user selectable AF points, 41 of which are cross-type points, and five dual cross-type points for extra precision. Quite a difference. Of course as with any complex machine which offers a plethora of options, choosing the best focus option for the job in hand is no longer quite as simple as it was. Af operation is supported with lenses f5.6 and faster. That means a 500/4 + 1.4x will AF (effective f5.6) but a 500/4 + 2x won’t AF (effective aperture f8).

The new 63 zone iFCL metering system (also used on the EOS 7D) is also an improvement, giving more reliable results in difficult metering conditions. “FCL” stands for Focus, Color and Luminance and indicates that the new system takes into account color by measuring and comparing red/green and blue/green signals, then combining the results to determine the overall best exposure. It may perhaps not quite equal the metering system of the EOS-1D X which uses 100,000-pixel RGB AE sensor with 252-zone metering and which is powered by a dedicated DIGIC 4 processor, but it’s better than the 35 zone system of the EOS 5D MkII, especially under tricky lighting conditions and/or for subjects with a strong color bias.

The EOS 5D MkIII also has a few new goodies for videographers. There is now a dedicated video start/stop button (as on the EOS 7D). There’s manual control of recorded audio level (with the level displayed on the LCD), and there’s a headphone jack for real time audio monitoring. Time codes are now embedded in video files and ALL-1 or IPB compression can be selected. There is, however no continuous AF during video shooting. For that you’ll have to downgrade to the new EOS Digital Rebel T4i.


The Canon EOS 5D MkIII is noticeably faster then the MkII was. Not only has maximum continuous frame rate risen from 3.9fps to 6 fps, but the overall operation of the camera seems faster with virtually instant response to any control input.


Using a fast UDMA 7 CF card, you can pretty much shoot large/fine JPEGs until the memory card fills with no interruption from the image buffer (Canon claim up to 16270 shots under their test conditions!). Shooting RAW you can get around 17 or 18 shots before the buffer slows things down to around 2.5fps. Shooting RAW + large/fine JPEGs the buffer holds around 7 shots and after that the frame rate falls to around 2fps. With slower, non-UDMA cards buffer size will be somewhat smaller (much smaller for JPEGs).

Though the EOS 5D MkIII can use both CF and SD memory cards, it seems that for the highest speed operation the fastest possible UDMA enables CF cards yield the best performance in terns of data transfer speed (and hence buffer capacity).

Canon claim that a fully charged LP-E6 battery should be good for around 950 shots or about 90 minutes of video. During my testing, after 222 shots in the course of about 2 hours, the camera’s battery info screen showed 86% of the charge remaining, which is pretty good! The shot capacity drops if Live View is used and Canon estimate around 200 shots in that case.


One of the major new features of the EOS 5D MkIII is the new AF system that it shares with the EOS-1D X. It takes manual 40 pages of rather small type to describe the AF system so I suggest that anyone who needs to know the full details should probably download the .pdf version of the manual from the Canon site. However I’ll try to give you at least some idea of how it can be configured.


The sensor itself has 61 AF zones. There are two outer zones each consisting of 20 sensors (40 in all) and 21 center zones. All 61 zones can detect horizontal lines with lenses as slow as f5,6. 20 of the outer zones (10 on each side) can also detect vertical lines with lenses as slow as f4. All of the AF zones in the center section can detect both horizontal and vertical lines with lenses as slow as f5,6. In addition 5 of the 7 sensors in the middle column of AF sensors in the center zone also have left and right diagonal sensors sensitive with lenses as slow as f2.8. Complex enough? Well as they say “you ain’t heard nothing yet”.

Some lenses can use all the sensors, some can only use a subset. In fact Canon lenses all fall into one of 8 groups (which Canon call Group A through Group H).

The group A lenses can AF with all 61 AF zones and can use all 5 cross and diagonal sensitive sensors. These lenses are basically the fast (f2.8 and faster) primes and zooms

The group B lenses can also use all 61 AF zones, but only the very center AF zone is capable of both cross and diagonal high precision AF. The group B lenses are the ultrawide primes (14/2.8, 20/2.8, 24/2.8, 24-70/2.8 and 15/2.8 fisheye).

The group C lenses also can AF with all 61 zones, but none can access the dual cross and diagonal center zone AF sensors – even if they are faster than f2.8. Most of the long f4 telephoto lenses are in this group, though the 50 and 100mm macro lenses are in it too.

I’m not going to go into detail of every group (see the manual for that), but once you get down to group F some of the outer zones become unusable and only 47 out of the 61 AF zones can be used. Most of these lenses appear top be older consumer zooms of the 28-70, 35-70 and 35-80 range. However the 800/5.6L IS is in there and so is the 35-500/3.6-5.6L

Group G lenses lose a few more outer zones and can only use 33 AF zones. There are two lenses in this group, the 180/3.5L macro and the 1200/5.6L

Group H is the saddest group. These lenses can only use the single central AF zone. However the only lens in this group is the 35-105/4-5.6 in both the USM and non-USM versions.

Within these parameters, AF can be setup to use a single AF zone, A zone plus adjacent horizontal and vertical zones (5 zones) or A zone with all adjacent zones (9 zones). You can also set AF to be one of 9 blocks of 12 contiguous zones or you can let the camera decide and have all 61 zones active.

So once you’ve selected the AF zone or zones you want, you can them customize the performance of the AF system with various combinations or subject tracking sensitivity, acceleration/deceleration tracking and AF point switching. There’s about 20 manual pages devoted to the various options, with presets for things like “subjects which accelerate and decelerate quickly” (Case 4) or “subjects which may change speed and move erratically” (Case 6) which combine different settings for tracking sensitivity, acceleration/deceleration tracking and AF point auto-switching

AF micro-adjustments are available for supported lenses.

By now you might get some idea of the complexity of the system. I suspect it takes a lot of study and practice to fully optimize the settings for any particular shooting situation. I’m sure it also gives the unwary photographer a lot of ways to get it wrong too!

All of the above describe the phase sensitive AF system used in normal reflex viewing operation. The EOS 5D MkIII is also capable of contrast sensitive AF when in Live View Mode. Face detection is available, where the camera will try to recognize and focus on a human face if it finds one. As Philip Greenspun pointed out in his first impressions review there’s no eye detection to make sure the closest eye is in focus. Whether or not you regard this as a serious omission depends on how you expect to shoot I guess. My gut feeling is that most EOS 5D mkIII photographers probably won’t be shooting with auto AF in Live View very often and only a small subset of them will really miss eye detection focus.

Note that there is no AF capability at f8, something the new EOS-1D X also lacks. Canon chose to improve low light AF at apertures of f5.6 and faster, but that meant that AF at f8 wasn’t possible.

So how well does it work? The answer is very well indeed. AF is certainly better than on the EOS 5D MkII, especially under difficult conditions such as low contrast or moving subjects in low light. The tracking AF also seems to be excellent, at least for the brief testing I was able to do while I had the camera in hand. By Canon’s own words it may not be quite as quick as the EOS-1D X is (the 1D X uses multiple processors dedication to nothing but AF).

There’s an excellent guide to the EOS-1D X AF system at and since the EOS 5D MkIII AF system is essentially the same, it also serves as an excellent guide for the 5D MkIII

On to Page 2: Exposure, Image Quality, Video…


The EOS 5D MkIII features an iFCL 63-zone Dual-layer Metering Sensor. “FCL” stands for ‘Focus, Color and Luminance’. With this system the metering measures color and luminance data, and also takes into account data provided by AF zone of the AF system.

The dual layer sensor separately measures the intensity of both red-green light and green-blue light. In addition the metering system takes into account which parts of the image are in focus. Even if the user has selected a single AF zone, data from all 61 AF zones are read. The metering algorithm then uses the color and luminance data, in conjunction with the focus data, to determine where the main subject is and what the optimal exposure for the whole scene should be.

In practice I found the multizone metering to be very reliable. Even in difficult lighting situations the camera seemed to chose optimum exposure. If anything I’d say the system tends to give slight underexposure rather than any overexposure, which is a good thing since it avoids unnecessary blowing out of highlight detail.

The usual Canon functions of Auto Lighting Optimization (ALO) and Highlight Tone Priority (HTP) are available (though they can’t be used together). HTP can be used over the ISO 200-25600 range and expands the dynamic range for highlights at the expense of slightly higher shadow noise. ALO automatically optimizes the image in terms of brightness and contrast.

The native ISO range of the EOS 5D MkIII is 100-25600, but this can be expanded to include ISO 50, 51200 and 102400. Auto ISO is also available and covers the range from ISO 100 to ISO 12800.


The 5D Mk III has in in-camera HDR mode which takes 3 shots at either 1, 2 or 3 EV intervals and then aligns and combines the images into a single HDR JPEG. It doesn’t do anything you can do by combining the 3 shots using external software, but for a fast HDR image or just to see how the HDR looks with the intent of using external software for a final image, it works well. You don’t need a tripod, though its probably better to use one if one is available. If you move the camera too much between the three exposures and the camera can’t align the images, the HDR process will fail. In all cases the original images are stored as well as the composite HDR image, so you can always use the original images and an external HDR program.

Image Quality


The EOS 5D MkIII uses an entirely new 22.1MP sensor. The EOS 5D MkII has a 21.1MP sensor, so clearly you wouldn’t expect much of a difference in resolution, and you don’t. The new sensor design is a little more efficient in terms of microlens coverage and active pixel area, so there is a small improvement in signal to noise ratio. I’d estimate this at maybe 1/2 stop for RAW files. JPEGs look cleaner out of the camera on the MkIII however, partly because of the improved SNR but also because the improved noise reduction algorithms and extra processing power of the Digic 5+ processor. Canon claim that JPEGs from the MkIII look up to 2 stops cleaner than those form the 5D MkII at the same ISO and camera settings

The extra noise reduction doesn’t come free though as there can be some loss of detail, especially in lower contrast area. Default setting JPEGs also seem to be slightly over-sharpened (bright lines around some edges when viewed at 100%). If you want to get the most out of the images shot with an EOS 5D MkIII you will want to shoot RAW and apply your own levels of noise reduction and sharpening either in Canon’s DPP software or another 3rd party application. It’s not that out-of-the-camera JPEGs aren’t good. They are. It’s just that carefully processed RAW images can be even better.

Noise reduction and sharpening of JPEGs can also be adjusted to some extent in the camera, but RAW image processing will still yield superior results when the final image is closely examined.


In practice I’d say that noise really isn’t an issue up to around ISO 1600. Some noise starts to become visible at ISO 3200 but even all the way up to ISO 12800 it’s quite manageable. At ISO 25600 it’s pretty clearly visible and the two expanded settings, H1 (51200) and H2 (102400) are probably best reserved for emergency use. However even at H2 (ISO 102400), small images are still acceptable. You just don’t really want to use it for those 24×36″ prints unless you’re looking for a “special effect”.


I’m no videographer so it’s hard for me to compare the video operation of the EOS 5D MkIII with that of other cameras. However the Canon EOS 5D MkII was the choice of many professional videographers and the EOS 5D MkIII is even better.

The 5D MkIII uses the same focus system for video that most of the other EOS cameras have. Focus is done by contrast detection while the mirror is up. The new EOS T4i has phase sensitive elements built into the sensor but the EOS 5D MkIII sensor doesn’t. This means that video (and Live View) focus is slower and that continuous AF tracking of a subject while shooting video isn’t possible.

The 5D MkIII adds a capability for audio monitoring (there’s a jack on the camera into which you can plug headphones) with audio level meters displayed on the screen. Apparently that’s something that serious videographers have been asking for and now they have it. Note that the built in microphone is mono, but there’s a jack for am external stereo mic.

The 5D MkIII also adds timecodes in fact it allows for two methods of SMPTE time-code embedding which makes it easier to synchronizing multiple-camera footage and audio in post-production. A feature not likely to be used by casual family video shooters, but probably something serious film makers would use.

The 5D MkIII allows the choice of two video compression schemes, IPB and ALL-1. IPB is basically a scheme which compares each frame with previous frames and only records and compresses the difference between the frames. ALL-1 compresses each frame individually, just like JPEG stills. IPB produces smaller files, but video quality may be slightly lower and it needs more processing power to display. ALL-1 results in larger files which need less computer processing power to play back, but the files are larger.

In practice it appears that the difference in image quality is fairly small, though serious videographers may prefer it not only for the slight quality advantage but because it’s easier to edit since each frame is already there, while with IPB compression most frames have to be reconstructed from a reference frame and the difference data.

The higher speed and more powerful processor of the 5D MkIII allows it to read all the pixels from the sensor before downsizing the image to video format. The 5D MkII wasn’t fast enough to do this so it had to skip lines. The result is that the 5D mKIII shows less of a tendency to show Moire patterns in areas of fine detail. Rolling shutter effects are also reduced.

Another nice feature for video is that there is an option for the rear QCD to become touch sensitive in video mode which enables silent modification of shooting parameters such as audio recording level (no clicks from buttons and wheels).

What it boils down to is that while the average amateur may be perfectly happy with the 5D MkII video, the more demanding videographer will appreciate the added features of the 5D MkIII.

On to Page 3: The D800 Factor, Conclusions, Samples…

The D800 factor….

The nikon_d800 was released at around the same time as the EOS 5D MkIII and since they are both full frame DSLRs aimed at the same market segment it makes some sense to compare them. The D800 has a 36.3MP sensor so it would be expected to be capable of showing higher resolution than the EOS 5D MkIII, and indeed it does. In tests that I did it appeared the resolution of the Nikon D800 was up to about 1.3x higher than that of the Canon EOS 5D MkIII, which is exactly what you would calculate from their respective pixel pitches.

In terms of image noise you might expect the D800 to be a bit noisier since it uses smaller pixels, but in fact it isn’t. Noise levels in properly exposed images, shot on RAW (NEF) and optimally processed are pretty similar at the same nominal ISO settings.

Where the D800 does shine over the EOS 5D MkIII is in deep shadow noise at low ISO settings. Where this is most obvious is with a severely underexposed image, say 4-6 stops of underexposure. When a severely RAW/NEF image is adjusted in a RAW developer such as RAWTherapee (or equivalent commercial software), the resulting image from the D800 shows significantly better color and lower and more uniform noise than an equivalent image from the EOS 5D MkIII.

I’m not going to discuss the various other factors that go into a camera or make any judgments about the relative overall merits of the EOS 5D vs Nikon D800, but I will say that I think the D800 has the better sensor when it comes to resolution and deep shadow noise at low to mid ISO settings (which translates into a greater dynamic range). Whether you would ever need to utilize that low noise deep shadow capability depends on how and what you shoot. It’s not something that’s visible in normally exposed and printed images.


The canon_5D3-body is an excellent camera and a significant improvement over the EOS 5D MkII in terms of usability. It’s faster, has better AF, better AE, better video, many more features, an extended ISO range and somewhat lower noise. In terms of absolute image quality the difference isn’t so large so if you’re a studio photographer shooting RAW images, working with static subjects in controlled lighting and you don’t shoot serious video, then you may not gain much moving from an EOS 5D MkII to and EOS 5D MkIII. However if you’re an outdoor photographer working in difficult light and trying to track moving subjects (e..g in sports and wildlife photography) then I’d think you’d find the EOS 5D MkIII a significantly better camera than the EOS 5D MkII and an upgrade may be well justified.

As a 7D user I found the EOS 5D MkIII control layout to be quite familiar and easy to use. Most of the common functions can be accessed with a single button push including Live View and Video modes.

The additional video features (audio monitoring, choice of compression schemes, embedded time codes etc.) probably wouldn’t be useful for the casual shooter of home movies but could well be important to budding cinematographers. It’s clear that the EOS 5D MkIII will be the model of choice for more serious film makers.

Canon also has a canon_5d-mkiii available.

The nikon_d800? Nice camera, built in flash, higher-resolution low-noise sensor and $500 cheaper. However for any Canon user with a collection of lenses it would make little sense to switch brands The 5D MkIII is a very good camera with fast operation, extended ISO range, excellent image quality, very good AF and a extensive feature set.

Where to Buy

When you are ready to buy, please help to support by purchasing through one of our retail partners.

canon_5d-mkiii. From the Canon website: Canon is proud to present the highly anticipated EOS 5D Mark III. With supercharged EOS performance and stunning full frame, high-resolution image capture, the EOS 5D Mark III is designed to perform. Special optical technologies like the 61-Point High Density Reticular AF and an extended ISO range of 100-25600 (expandable to 50 (L), 51200 (H1) and 102400 (H2) make the EOS 5D Mark III ideal for shooting weddings in the studio or out in the field, and great for still photography.


16135512 This series of 100% crops from shots taken with a Canon EOS 5D MkIII shows the effect of ISO on image noise. Things are pretty clean between ISO 100 and ISO 1600. Between ISO 3200 and ISO 12800 noise steadily increases, but is manageable. At ISO 25600 and above noise starts to dominate the image. All these crops were taken from default JPEG files. Custom noise reduction is possible on RAW files.
15275493 The optional BG-E11 grip is shown mounted on the EOS 5D MkIII. The BG-E11 grip allows the use of two Li-ion batteries or 6 AA cells to power the camera and provides an extra 4 way controller, shutter release and several other control buttons
15275495 The connections on EOS 5D MkIII include a jack for an external stero microphone, a jack for monitoring the recorded audio, A PC flash connector, A connector for a wired remote, An HDMI port and a digital and A/V out port
16135753 If you shoot a still while recording video with the EOS 5D MkIII, the video pauses and the still image is recorded in whatever still mode is set (JPEG, RAW, RAW+JPEG). The JPEG is automatically cropped to the video aspect ratio, but the full frame RAW file is recorded.
16135752 The bright orange fluorescent road sign doesn’t seem to have upset the metering system of the EOS 5D MkIII

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    • Nice article. I suggest a small correction - the AF of the original 5D traces its origins to the 20D, not the 30D - the 30D was announced in February 2006, after the 5D (August 2005).

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    • That's correct. The 5D AF was derived from that of the EOS 20D (which went on unchanged to the 30D). I say "derived from" because though it was superficially the same 9 zone center-cross system as that of the 20D, there were in fact 6 "invisible" AF assist zones around the center zone of the 5D (and 5D MkII).

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    • I am somewhat confused that you say AF is not available at F8. I was aware of an issue with the 1DX but not the 5D mk 3. So I picked up my mk3 and I have no problem with F8 and AF, unless I have gone mad, can you help. 

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    • I can't say what you're doing, but the 5D MkIII will not AF with any lens that has a maximum aperture slower than f5.6. That would include any f5.6 lens with a Canon 1.4x TC or any f4 lens with a Canon 2x TC.


      Obviously all cameras will AF with the aperture set to f8 (or f11, or f16 etc) as long as the MAXIMUM aperture of the lens is f5.6 or faster because AF is always done with the lens wide open, not stopped down.


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    • My apologies I had gone mad as suggested, I read that part of the review totally wrong, sorry

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    • Not sure why they added a 'Rate' button, is that suppose to be hip ?

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