In terms of performance the EOS 5D Mk2 is, as you might expect, enormously impressive, but it is not without its faults. Start-up time is very quick even by DSLR standards, with a delay of less than half a second between switching the camera on and it being able to focus and take a picture. The main nine-point AF system is so quick in good light that it is virtually instant, however it is considerably slower in lower light and I did find it hunting around a bit from time to time in late evening light conditions.
In single-shot mode the shot-to-shot time approximately 0.4 seconds, but in practice it can take pictures just as fast as you can press the shutter button, although if you're shooting in maximum-size Raw+JPEG the it is possible to fill up the image buffer after 17 shots if you can press the button fast enough. In continuous mode it can hit the advertised 3.9 frames per second, but only in JPEG mode, however switching to Raw+JPEG mode barely slowed it down at all, managing approximately 3.6 frames per second with a 2GB SanDisk Extreme IV CF card. The number of shots that can be taken in a burst depends on the recording mode. The EOS 5D Mk2 has three different Raw file settings; a standard full-size 21-megapixel mode and two smaller modes shooting 9.9MP and 5.2MP Raw files respectively. In JPEG-only mode the burst size is limited only by the memory card capacity, while in all Raw+JPEG modes it is limited to nine frames before the frame rate drops to approximately 1.5fps, while shooting in Raw only the buffer is large enough for 17 shots before the frame rate drops.
One aspect of the camera's performance that may be a cause for concern is its appetite for memory cards. In full-size Raw+JPEG mode the combined file size is around 30MB, with the two smaller modes clocking in at 17MB and 13.5MB respectively, with the JPEG-only file size averaging between 5 and 10MB. This means that in the maximum quality mode, which of course most photographers will prefer, a 1GB memory card is only enough for 26 shots.
There is so much to talk about with this camera that I could probably fill another couple of pages and still miss something, but time and space require that I wrap things up, which brings us finally to the vital subject of image quality. As potential buyers (hi Riyad!) will be delighted to hear, the 5D Mk2 performs brilliantly. It has essentially the same sensor as the £5,800 EOS 1Ds Mk3, but the 5D Mk2 pairs it with the more advanced DIGIC 4 processor. From what I've seen of the output of the 1Ds, the 5D actually seems to have marginally superior image quality, particularly in the area of image noise control. I won't beat around the bush with superfluous details when you can look at the following sample images for yourself, but suffice to say that the EOS 5D Mk2 has by far the best image quality of any digital SLR I've ever used, and makes APS-C DSLRs look like compact cameras by comparison. The tonal range, depth of colour and the sheer level of fine detail are simply amazing, and the noise control is better than I would have believed possible. There is a faint hint of noise visible at 800 ISO, but images as high as 3200 ISO are perfectly printable, and even the 12,800 ISO extended setting there is still a surprising amount of detail visible.
I'm looking forward to testing a Sony Alpha A900 very soon. I've heard very good things about it, but it's going to have to go some if it's going to beat the EOS 5D Mk2.
The Canon EOS 5D Mk2 represents the state of the art of current digital SLR design. Its combination of professional-level build quality, superb handling, high-speed performance, class-leading image quality and the added bonus of HD video recording and its other advanced features will be more than enough to satisfy even the most demanding photographer, and it is sure to match the popularity of its illustrious predecessor.