Canon EOS-1D Mark IV at a glance:

  • 16.1 million effective pixels
  • APS-H-sized (27.9×18.6mm) sensor
  • 10fps continuous shooting
  • New 45-point
  • AF system
  • Street price approximately £3,740

Canon had quite a torrid time with its EOS-1D Mark III, which was announced in February 2007. First, there were the notorious AF issues, with some users claiming that the camera couldn’t follow focus as well as its predecessor, the EOS-1D Mark IIN. Initially, Canon batted these concerns away, saying the problems reported by some professionals were a result of them not understanding or correctly selecting the various custom modes. This may have been a fair point in certain cases, but it soon became apparent that the camera also had problems that had to be addressed by a couple of firmware upgrades as well as the recall of some bodies.

To make matters worse, Nikon created quite a stir in August 2007 when it announced the D3 and D300. Nikon had made a huge leap forward with the introduction of the full-frame, 12.1-million-pixel D3, with its maximum sensitivity setting of ISO 25,600, 9fps continuous shooting and 51 AF points. Subsequently, the ten-million-pixel Canon EOS-1D Mark III, with its sub-full-frame (APS-H-sized) sensor, started to lose its appeal despite its 10fps shooting rate. Unfortunately for Canon, many professional photographers chose to switch systems and use Nikon equipment.

Clearly, Canon has learned a few lessons in the intervening period. Its recent DSLRs have indicated a change in its ethos, as new systems and technology have been introduced to make the company’s cameras even more competitive. For the latest camera in the EOS-1D series, the EOS-1D Mark IV, this has meant a completely new AF system, a 16.1-million-pixel APS-H-format sensor and a maximum sensitivity setting equivalent to ISO 102,400, which matches that of Nikon’s D3S. It could be the riposte that Canon has been searching for.


Although the EOS-1D Mark IV is quoted as having an APS-H-sized sensor like its predecessor, it is interesting that the dimensions of the imaging device have actually shrunk marginally from 28.1×18.7mm in the EOS-1D Mark III to 27.9×18.6mm in the new camera. As before, this puts it between an APS-C and a full-frame device, and it produces a 1.3x focal length magnification factor. However, this isn’t the only difference between the two sensors. For many people, the most important point is that the effective pixel count has been increased from 10.1 million to 16.1 million, and this has necessitated a drop in pixel size (in microns) from 7.2×7.2µm to 5.7×5.7µm.

This could have negative repercussions for the signal-to-noise ratio, but Canon has introduced a range of measures to help minimise image noise levels. For instance, the photodiodes occupy a greater proportion of the pixel area to increase the size of the light-receiving area and a new material has been used for the primary colour filter to boost light transmission. As with the EOS 7D and EOS 550D, the microlenses over the EOS-1D Mark IV’s sensor are gapless and closer to the photodiode than before to boost light capture. Canon also claims that noise suppression has been improved and that doubling the internal gain of the preamp helps increase the signal-to-noise ratio.

All these measures, plus improvements brought by the switch from dual Digic III to dual Digic 4 processors, means Canon has felt confident enough to give the EOS-1D Mark IV a sensitivity range of ISO 100-12,800, which can be expanded to the equivalent of ISO 50-102,400. The impressively high maximum sensitivity setting matches the highest value possible with the camera’s main competitor, the Nikon D3S.

The EOS-1D Mark IV is primarily aimed at photojournalists and sports photographers who demand a high continuous shooting rate. Despite its much higher pixel count, the EOS-1D Mark IV is capable of shooting at the same maximum rate – 10fps – as its predecessor. This gives the Canon camera a 1fps advantage over the Nikon D3S.

Given the problems with the EOS-1D Mark III’s AF, it is hardly surprising that Canon has introduced a completely new system for the EOS-1D Mark IV, with new hardware and firmware. I will cover this in greater detail later, but the important aspects are that it has 45 user-selectable points, with 39 being f/2.8-sensitive cross-type.

Video-recording technology is fast becoming essential in a photojournalist’s camera and the EOS-1D Mark IV can record movies as MOV files at three sizes. These are 1920×1080 pixels (Full HD), 1280×720 pixels (HD) and 640×480 pixels (SD) with MPEG-4 AVC compression and a selection of frame rates available at each size.

With such a well-specified camera it seems almost churlish to point out that the EOS-1D Mark IV doesn’t have a built-in level like Canon’s top-end APS-C-format DSLR, the EOS 7D, or the Nikon D3S. And now that Canon has finally seen the light and introduced wireless flash control via the pop-up flash unit of the enthusiast-level EOS 7D, perhaps it is time for the company to include the technology found in its ST-E2 Speedlite Transmitter in a professional-level DSLR.

Continuous shooting

Image: This sequence of consecutive images is an extract from a series of 19 taken at 10fps. The AF system kept the player in white perfectly sharp in all but one shot

Like the camera it replaces, the EOS-1D Mark IV has a top continuous shooting rate of 10fps. This is made possible by the two Digic 4 image processors, eight-channel signal readout, DDR2 SDRAM buffer memory, a twin motor system (one for cocking the mirror and the other for shutter cocking), and an active mirror stopper to suppress mirror-bounce and maintain a steady viewfinder image.

With a UDMA (90MBs or 600x) CompactFlash card installed, I found that the 121 maximum burst depth for large JPEG files quoted by Canon is reasonably conservative and I was able to record more than 250 highest quality, large JPEG images, and even 289 on one occasion. However, I was only able to shoot nine raw files before the camera faltered.

Shooting in excess of 280 images involves holding the shutter-release button down for around 28 seconds. During this test I found that even when shooting the action of a football match, I only shot continuously in bursts of 5secs or less, but it’s good to have the option to shoot more. Photographers shooting athletics events, for example, may appreciate the ability to record entire 100m
and 200m events.

Although I am sure the sound of the EOS-1D Mark IV firing continuously would alert a nearby deer to a photographer’s presence, the mirror-movement dampening is much better than that in the Sony Alpha 900.

Build and handling

At the risk of stating the obvious, the EOS-1D Mark IV is a big camera as, like its forebears, it has both vertical and horizontal grips built-in. These make the back of the camera much squarer in shape than the models below it in the Canon DSLR line-up, so users trading up to the EOS-1D Mark IV may find that they need to invest in a bag that is able to accommodate their new toy.

The new camera has the same magnesium-alloy construction and 76 dust and waterproof seals as the camera it replaces. It feels very solid and built to last. However, by my calculations the quoted 300,000-cycle shutter durability only equates to around 8 hours and 20 minutes’ use at 10fps. While this would be an exhausting single shoot, it doesn’t really seem that long for the expected life of a key component of a professional sports photographer’s camera.

Despite the introduction of video-recording technology, Canon has kept the construction and control layout of the EOS-1D Mark IV very similar to the Mark III version, but there are a few little tweaks that have been made in response to feedback from users. Many of the buttons on the back of the Mark IV, for instance, have been made more prominent and require a longer, firmer press so they are easier to locate and have a more positive feel.

The mini-joystick multi-controller has also been made more pronounced so it is easier to operate. In addition, small holes have appeared in the back of the vertical handgrip and the far right of the front of the camera to allow the inclusion of a speaker and internal microphone respectively.

While EOS-1D Mark III users may appreciate the similarity of the EOS-1D Mark IV’s control system, I am surprised there isn’t a dedicated Live View and video-recording button with a switch to determine whether still or movie footage is to be recorded. This was a welcome introduction with the EOS 7D and I suspect that the journalists using the EOS-1D Mark IV are even more likely to need to switch quickly between recording modes than EOS 7D users.

There are, however, two ways to start video recording, depending upon the option selected for Custom Function IV 11. The default mode is to activate Live View mode with a press of the Set button at the centre of the Quick Control dial on the camera back and then start video recording by pressing the flash exposure lock (FEL) button that sits near the shutter release. Alternatively, the FEL button can be used to start recording directly, but this is at the expense of its flash-exposure lock role.

I found the EOS-1D Mark IV easy to get to grips with, and on the whole its controls are sensibly arranged and within reach. As with the EOS-1D Mark III, though, the mini-joystick multi-controller, which I generally use to select the active AF point, is out of reach when the camera is rotated through 90° and my finger is poised over the shutter-release button on the vertical grip. Rather unhelpfully, the menu and information screen don’t rotate when the camera is held in this orientation.

Although the menu is extensive and there are 62 custom functions, the options are sensibly arranged and grouped so it doesn’t take too long to become familiar with the layout and find what you need. However, given the complexity of the AF system, I think Canon should revisit this section of the custom menu and make the function of the various options a little clearer. Fortunately, up to three sets of custom functions can be saved and recalled, which is very useful and allows the photographer to switch quickly between working arrangements.

The My Menu screen is also helpful for some of the more frequently used, or heavily buried, menu functions, such as the mirror lock-up or the AF AI Servo Tracking sensitivity (Custom function III: Autofocus/Drive 2).

Resolution, noise and sensitivity

These images show 72ppi (100% on a computer screen) sections of images of a resolution chart, captured using matching 105mm macro lenses. We show the section of the resolution chart where the camera starts to fail to reproduce the lines separately. The higher the number visible in these images, the better the camera’s detail resolution is at the specified sensitivity setting. 

When Nikon announced the launch of the D3S, it raised the bar for noise control and sensitivity. Canon has matched the D3S’s maximum sensitivity setting of ISO 102,400 for stills and video capture with the EOS-1D Mark IV, but the results are extremely noisy.

When the noise reduction is turned off the level of noise is off the scale of our testing regime, so we are unable to report meaningful figures at ISO 51,200 and 102,400. Even in the raw files, detail resolution is heavily compromised at these highest expansion settings and I would avoid using the ISO 102,400 option.

Noise is well controlled up to around ISO 1600. Between this point and ISO 51,200 (inclusive), JPEG files taken with the noise reduction set to its default standard level have more chroma and luminance noise than comparable JPEGs from the full-frame, 12-million-pixel Nikon D3S.

Although the level of noise in JPEGs captured by the Canon camera at ISO 102,400 with the noise reduction set to its default level is lower than that in JPEGs from the D3S, the EOS-1D Mark IV’s files contain much less detail.

Green and red splodges are visible in the Canon camera’s images, especially in the shadows, even when they are sized to make small prints.

At more routine sensitivity settings, the EOS-1D Mark IV is capable of recording a high level of detail.

UNDERSTANDING THE GRAPH This graph shows the brightness values recorded by the test camera when it is used to photograph a stepped graduation wedge. The wedge has transmission values in 1⁄2EV steps ranging from 0 to 12EV. The camera’s exposure is set so the 12EV section in the wedge has a brightness value of 255. Software analysis of the image then determines the recorded brightness values of all the other steps and calculates the camera’s dynamic range.

Dynamic range

At face value, a measured dynamic range of 10.5EV seems low for the EOS-1D Mark IV, but I didn’t notice any restriction in the range when shooting real-world photographic images. The fairly steep mid-section of the dynamic-range curve indicates good midtone contrast, which helps convey the impression of detail. At the shadow end the curve dips sharply, indicating a compression of the tones in this area.

In keeping with Canon’s other DSLRs, the EOS-1D Mark IV has both Highlight Tone Priority (HTP) and four levels (including off) of shadow-boosting Auto Lighting Optimiser (ALO). As with the EOS 550D and EOS 7D, these options can’t be used simultaneously.

Although it can be difficult to predict the degree of lightening that will be seen when ALO is employed, it can be useful when there are important details that need bringing out in the shadows. When contrast is high it can help photographers produce print-ready images direct from the camera, thus saving time at the computer.

Viewfinder, LCD, live view and video

As an APS-H-format camera, the EOS-1D Mark IV has a smaller viewfinder than the full-frame EOS-1Ds Mark III. However, it offers an approximately 100% field of view with 0.76x magnification. This is interesting as the APS-C-format EOS 7D also offers a 100% field of view, but it has 1x magnification, which means its viewfinder is slightly larger. Nevertheless, the EOS-1D Mark IV’s viewfinder is very clear and bright, and it is easy to focus manually when viewing the scene through it.

Camera LCDs have moved on a little since the EOS-1D Mark III was launched and the Mark IV camera’s screen has a much higher resolution with 920,000 dots (307,000 pixels).

Like the EOS 7D, the space between the crystals and the reinforced glass cover (previously acrylic) of the EOS-1D Mark IV’s 3in LCD screen has been filled with an optical elastic material to reduce reflections and glare. In addition, the EOS-1D Mark IV’s monitor has an anti-reflective coating that isn’t present on the EOS 7D’s screen. As a result, when the EOS-1D Mark IV is turned off, the screen looks absolutely black and it is possible to view images on it even in quite bright ambient light.

To meet the demands of many professional photographers, the EOS-1D Mark IV is video enabled and exposure can be controlled manually, or automatically by the camera. The frame rate for Full HD (1920×1080-pixel) footage can be set to 30p, 25p or 24p fps. Faster frame rates are available for the smaller image sizes. The appearance of the footage may be changed by altering the selected Picture Style, and the effects of dynamic-range-enhancing Auto Lighting Optimizer are also applied along with the Peripheral Illumination Correction if it is activated.

High-quality video capture is possible, but as usual the built-in monaural microphone is prone to recording hand movements and lens noises, so it is advisable to connect an external mic via the 3.5mm stereo port.

White balance and colour

Canon has one of the best, if not the best white balance system currently available and it didn’t throw up any surprises during this test. When shooting in early evening shadow, my images taken with the automatic white balance settings are suitably cool, without being excessively cold – which appears to confirm Canon’s statement that the AWB has been made more neutral and less warm. My shots taken when shooting under the artificial lighting of a night-time velodrome have a slight warmth that suggests the lighting isn’t natural, but without spoiling the images.

Like Canon’s other DSLRs, the EOS-1D Mark IV has a collection of Picture Styles (Standard, Portrait, Landscape, Neutral, Faithful and Monochrome) that may be used to adjust the appearance of JPEG images. As usual, the Standard option is a good starting point and it produces vibrant but natural-looking images. Canon has increased the level of sharpening and saturation that is applied in-camera to make images more ‘press ready’, so that a sharpness of 3 on the EOS-1D Mark IV is equivalent to a setting of 5 on the EOS-1D Mark III.

However, those who want to specify the processing that is applied to the JPEG files can opt to tweak the sharpness, saturation and contrast settings for any of the colour Picture Styles, or save three of their own Picture Styles in-camera. Alternatively, the bundled Picture Style Editor software can be used to produce a bespoke image style that can be saved and registered to the camera.


According to Canon, although the EOS-1D Mark IV has the same 63-zone metering system as the camera it replaces, its evaluative metering algorithm has been altered to make it less dependent upon the subject.

However, when shooting a football match with a team in white against a team in mid-green, I noticed that the exposure varied depending upon what colour shirt the active AF point was over.

When a player in white was the main subject, the shirt was accurately exposed and looked white, not grey, with no flashing highlight warning on the LCD screen.

When the AF point was over a green shirt, however, the camera often selected an exposure that resulted in some of the opposing team’s kit being burnt out and the highlight alert could be seen flashing on the brightest parts of the image.

Consequently, I found it safer to reduce the exposure by 2⁄3-1EV. This meant that some of the images needed brightening post-capture, but they survived the process and look good. In most situations, though, the evaluative metering does a very good job.

Image: I increased the exposure suggested by the evaluation metering system by 1/3EV to introduce some highlights on the droplets and then darkened the sky in Photoshop to get the result I wanted


Image: This JPEG image was taken at ISO 12,800 with the high-sensitivity noise reduction set to Standard. The details are softened a little and some chroma noise is visible, but the result is nevertheless impressive 

As I mentioned earlier, Canon has introduced a completely new 45-point autofocus system for the EOS-1D Mark IV, with the primary aim of making it more stable than the EOS-1D Mark III’s AF system when focusing continuously in AI mode. While the EOS-1D Mark III has 45 AF points, only 19 of them are user selectable, whereas any of the Mark IV’s 45 AF points may be selected for focusing. Of these points, 39 are cross-type (the EOS-1D Mark III has 19 cross-type points) and function with all f/2.8 or faster EF lenses as well as some f/4 EF optics. In a bid to improve focus-tracking reliability and precision further, Canon claims the f/2.8-sensitive line sensors have been improved and some of the f/5.6-sensitive AF points have two lines.

There are 15 custom functions that govern how the AF system works. In the main, these are designed to tailor the camera’s response when shooting moving subjects and using the continuous AF mode. The most important functions allow the photographer to adjust the speed with which the camera reacts to a change in subject distance, determine which AF points are used to track it and to specify whether to prioritise using the main AF point or tracking the subject using the expansion AF points.

Canon attributes some of the reported continuous AF problems encountered with the EOS-1D Mark III to the fact that it has a very responsive system and this means that it is less likely to keep fast-moving subjects sharp if they cannot be kept within the AF frame. The manufacturer has reworked the AI Servo AF algorithm, calling the new version AI Servo II AF, to help make continuous AF more consistent and stable. EOS-1D Mark III users who upgrade to the EOS-1D Mark IV will also notice that the impact of the AF AI Servo Tracking sensitivity settings (Custom function III: Autofocus/Drive 2) has changed with a general slowing of the response time.

I used the EOS-1D Mark IV in a range of conditions designed to test the AF system. Not surprisingly, it struggled the most when I was shooting fast-moving cyclists at an outdoor velodrome after sunset and under fairly poor floodlighting, but I was still able to obtain sequences of sharp shots. When using an EF 70-200mm f/4L IS USM, which doesn’t support the full cross-type AF point functionality, I found the AF system a little sluggish (relatively speaking), and when Custom Function III: Autofocus/Drive 3 is set to give focus tracking priority (the default ‘0′ option), the shooting rate sometimes dipped below 10fps.

I noticed a significant increase in the speed of the AF response when the AF AI Servo Tracking sensitivity was pushed to its highest value so the camera reacted quickly to changes in the subject distance. However, when shooting fast-moving subjects at up to 10fps it is easy to be fooled into thinking that the active AF point is consistently over the main subject. It is only when the shots are played back on the LCD screen that it becomes clear that the AF point has often shifted to one side. Although there were a few short bursts where the camera failed to latch on to a cyclist when the light was at its poorest, the subject is acceptably sharp in 75-85% of my images.

Shooting the cyclists in brighter light and/or with an EF 300mm f/2.8L IS USM that supports the full cross-type AF point functionality improves the continuous AF performance significantly. As a result, I also noticed that the camera was able to shoot continuously at its maximum rate more often. It becomes much easier to get sharp ‘grab-shots’ of a moving subject without tracking it for a while in the viewfinder. With slightly slower moving subjects, such as footballers, the hit rate is higher, with only two or three shots in every 20 or so being
a little off target.

The competition

Image: Nikon D3S

The only direct competition for the Canon EOS-1D Mark IV is the Nikon D3S, which can be found for around £3,580. As well as a very effective 51-point AF system, the D3S has superb low-light capability and excellent noise control, but at 12.1 million its effective pixel count is around four million fewer than that of the Canon camera.

It would take a head-to-head test to be certain, but the D3S appears to produce better results at the higher sensitivity settings.

The D3S’s maximum continuous shooting rate is 1fps lower than that of the Canon camera, but this is unlikely to be a major deciding factor for many professional photographers.

Despite the issues surrounding it, there are many satisfied EOS-1D Mark III users and it is an affordable alternative to the Mark IV.

New bodies can still be found at around £3,000, while mint-condition second-hand examples fetch around £1,900. It has only ten million pixels, but that is enough for A3 prints and the image quality is very high.

Image: Canon EOS-1D Mark III


In many situations the Canon EOS-1D Mark IV captures superbly detailed images with natural, yet punchy colours. The AF system performs well, even in low light, although it is worth paying for fast lenses that get the best from it. Users also need to spend time experimenting with the system so the right options are selected for each subject and situation.

Comparing the results from the EOS-1D Mark IV at ISO 102,400 with those from the Nikon D3S suggests that Canon has felt the need to match its competitor’s maximum sensitivity setting, even though the image quality is short of what we usually see from a Canon camera. I recommend keeping to the native sensitivity settings where possible.

Canon has said that it wants to ensure EOS-1D Mark III users have an easy transition to the EOS-1D Mark IV, which I understand, but I am surprised that the manufacturer hasn’t taken the opportunity to introduce some of the changes we have seen lower down its DSLR line-up. To be fair, these are refinements to a system that works very well and if I had a spare £3,800 I’d be very tempted by the EOS-1D Mark IV.

Canon EOS-ID Mark IV – Key Features


In addition to evaluative metering, partial, spot and centreweighted average metering are available. Partial metering measures from an area at the centre of the scene, covering about 13.5% of the viewfinder. The spot meter lacks the precision of some other cameras and covers an area of around 3.8% of the viewfinder area.

Video recording
At 1920×1080 pixels (Full HD), video may be recorded at 30p, 25p or 24p fps, while 60p or 50p fps recording is possible at HD (1280×720 pixels) and SD (640×480 pixels) resolution.

FEL button
This can be used to start video recording, lock flash exposure or for taking multiple spot meter readings.

Peripheral illumination correction
Data for 29 lenses is pre-installed, but data for up to 40 lenses can be stored so corner shading can be corrected automatically.

Function button
This button provides access to the white balance and memory card/image size and quality options.

Vertical grip with speaker hole
The buttons to the right provide control over the AF, exposure lock and image magnification when the camera is used in the vertical orientation.

Three raw file sizes
There are three raw file sizes available on the EOS-1D Mark IV: four-million-pixel (2448×1632-pixel) S-raw, a nine-million-pixel (3672×2448-pixel) M-raw (Medium-raw) option and the standard 16-million-pixel raw size (4896×3264 pixels). There are also four JPEG image sizes and ten compression ratios.

Memory cards
The EOS-1D Mark IV has two card slots, one for CompactFlash and the other for SD (and SDHC) media. The photographer can specify how images are saved when both slots are occupied. Images can be stored at different sizes or formats (JPEG or raw) on each card, or movies can be stored on one card and still images on the other.