Canon 1D Mark IV review
One quirk of the Mk IV is that, like 1D models before it, it uses an APS-H sized sensor. This gives a crop of 1.3x on the image size, and makes focal lengths appear longer than on a full frame camera - though not to the extent of an APS-C (1.5 or 1.6x) sensor. This smaller form sensor has its benefits and its flaws: the 1.3x crop means that photographers can use smaller and lighter lenses than on full frame, or get in closer, but it does mean that photosites on the sensor are not as large, which can affect tonality. The sensor features 16.1 million effective pixels and is a CMOS design featuring Canon's integrated cleaning system, while Dual DIGIC 4 processors are used to maintain the high frame rate even for 14-bit Raw files. Images are output at 4896 x 3264 in Raw or JPEG, with smaller formats available in JPEG and Canon's unique mRaw and sRaw formats.
The ISO range is truly impressive - 102,400 ISO is nothing short of staggering and in real world terms offers five stops more light than the ISO 3200 offered by the original 1D in 2001. This roughly translates as a shot at 1/30th sec at 102,400 which at 3200 would need 1sec. The 1D Mk IV also offers an ISO 50 equivalent for those wanting to increase shutter speed or if shooting in bright conditions. Like other recent EOS models, there is an Auto ISO which allows you to specify a range of ISOs to use from the custom menu.
Metering is handled by Canon's 63-zone SPC system and offers a choice of evaluative, partial and spot. The spot metering can use the centre point, the AF point, or multiple selected points (a total of eight). Exposure compensation is just +/-3EV, rather than the more popular 5EV, at 1/3 or ½ stops. Auto bracketing offers the same range for two, three, five or seven shots.
These shots taken at the NME club night at London's Koko really tested the metering system but still managed to deliver some stunning results.
Canon 24-105mm f/4, at 24mm, f/4, 1/400th, ISO 12,800, AWB, Evalutive Metering
The focusing system is one of the most important parts of this camera for the sports photographer, as fast-moving subjects or chance moments need to be captured quickly. What on the face of it may seem a fairly simple two-stage option of single shot or servo is backed up with a complex maze of fine-tuning options to allow the camera's AF performance to suit your type of photography. The custom menu allows you to adjust the speed that the AF shifts focus when a subject moves into or out of the selected focus point. It allows you to select the expansion of the AF points for tracking: from none to all 45. You can specify your focusing priorities; whether it's with your selected point, the tracking, waiting for the focus to lock-on, or just taking the shot instantly - for that once-in-a-lifetime moment.
White balance is managed by five presets plus an Auto mode. There's also manual selection in Kelvin, five custom settings and a four-axis colour adjustment. Shooting modes are reassuringly simple with the choice of a standard M, Av, Tv, P, and Bulb. The drive modes offer a one shot, continuous (high and low), self-timer (2 or 10 secs) and a silent shooting mode to reduce mirror noise.
The viewfinder offers 100% coverage but, due to the sensor size, magnification is less than on full frame models, meaning a smaller view. The rear LCD screen has increased in resolution from the 1D Mk III and now offers 920,000 dots on the 3in Clear View II display. This is also coated to give an even brighter and sharper look. Within the live view you have a choice of two autofocus modes: Quick, which flips the mirror back down briefly to use the AF sensor, or Live, which uses contrast detect on the image sensor. There is also a face detection option. For video functionality you need to switch from stills to movie in the menu first. The video mode records in H.264 MOV (quicktime) and offers a full 1080P resolution (1920 x 1280) at 30, 25, or 24 frames per second for a maximum of 29min 59secs per clip. Functionality is otherwise limited to manual focusing and exposure compensation, with no independent control of aperture or ISO. It does offer an external mic input, however, for improved sound recording.
For output it features both an HDMI port and a high speed USB port. There's also a PC sync socket for attaching to external flashguns and studio lights, a terminal for a remote, and attachment for a wireless unit.