The EOS 550D presents me a problem. When I first compared the video capture from Canon and Nikon’s entry-level HD-DSLRs, I went with the latter and began experimenting with the D5000. It had regular 24fps video and a degree of manual control, with good frame quality despite the limit of 720p resolution and five-minute maximum take length.

While earlier Canon pro/am level HD-DSLRs have always offered longer video recording due to their .MOV file format, its 500D model was limited to an odd 20fps/1080p setting (it didn’t have the processing power, or card writing speed, to handle 1080p at the industry standard choices of 24, 25 or 30fps). Nor did it have an external microphone socket, which until the arrival of the 550D was the main feature distinguishing consumer models from professional.

Canon’s latest upgrade, the 550D, has everything that was missing from the 500D – 1080p capture at 24, 25 or 30fps with built-in mono or plugged-in external stereo microphone, useful manual control of video settings and single takes up to 4GB in data size. And it adds an 18.9 megapixel APS-C (1.6×) CMOS sensor, which appears to offer even better image quality than the more expensive EOS 7D, an improved metering system derived from the 7D, and an AF system that works well without the need for elaborate custom settings. It does this in a travel-friendly, lightweight body with improved ergonomics and the highest resolution three-inch rear LCD yet seen (more than a million pixels instead of 920,000, and a true 2:3 format at 720×480 instead of 640×480). And it does all this for around £600-700 street price, depending on whether you buy just the body or a kit with the handy 18-55mm IS lens.

What it lacks is instant access to video (which must be set on the mode dial) or a dedicated video shutter release button positioned near the main release, as in the more robust, professional orientated 7D and 1D Mk IV. Instead, it uses the conventional rear button, repositioned to fall better under the right thumb. Those who shoot for libraries such as Getty or Alamy will welcome the final 18 megapixel file size (more than 51MB in eight-bit RGB), which needs no interpolated scaling. They will also welcome the exceptional high ISO performance and dynamic range of this sensor, with its gapless micro-lenses. ISO settings from 200 to 6400 can be extended to 100-12,800.

The 18 megapixel sensor yields lower noise than the similar sensor in the 7D, and Canon confirms it is not identical. The optical viewfinder, though small, is very clear with the benefit of new screen technology and an unobtrusive AF display. The rear LCD’s live view autofocus and magnified manual focus is the best in its class, although it’s a pity Canon continues to eschew articulating screens like the Nikon D5000. This apart, the EOS 550D ticks all the boxes Nikon has left unchecked.

Nothing missed
Canon has tried to avoid criticism of deliberately omitted features with the 550D – the features that persuade buyers to spend more on a 7D. The 550D has a mirror-up delay timer function (absent all too often at entry level), remote and tethered operation, ±2EV 3-shot auto bracketing and 0.5/0.3EV factorial exposure compensation, all the usual modes and picture styles.

Where the USB port in many video-enabled DSLRs has been downgraded to operate only for data transfer, direct printing or tethered shooting, the 550D retains a dual-purpose AV-USB port that can supply audio and video out using the supplied S-VGA breakout cable. The HDMI port can send 720×480 pixel live view to suitable monitors; wireless or wired remote control can actuate autofocus; and a menu item enables Wifi file transmission using Eye-Fi SD cards. All this combined with its light weight makes the 550D ideal for robotic, aerial mast, hazardous environment, underwater drone and similar applied photography, without expensive adaptation or custom peripherals. A simple radio frequency wireless remote and the Eye-Fi function are all that’s needed for completely wireless image capture, with test shots serving as composition previews.

The LP-E8 battery is compact, as are the batteries for other small-bodied Canons from the 1000D through to the 450D. While it claims more than 400 shots maximum (a modest standard), or just 150 per charge using live view, no specific capacity is given for video. I found that it is rapidly exhausted – a few dozen raw shots and 20 minutes of 1080/24p can leave you with a “Replace Battery Now” message next time you switch on. Spare batteries, or a battery grip (BG-E8) taking AA cells, are essential.

Some of Canon’s previous entry-level models, which use a similar small battery, have needed a dummy battery with a ribbon cable to act as a crude DC-in connection. The 550D has a separate DC-in socket, providing a more functional mains power supply. This is very useful for studio video shooting, playback, and tethered operation.

Card problems
Eye-Fi cards, like others, come in various speeds. The EOS 550D is the first camera I’ve tested that was not fully compatible with any of my existing SD cards, despite the fact these cards claim to be the Class 6 that the camera officially needs.

Still shooting, which should be at up to 3.7fps even for 14-bit raw .CR2 files, was slowed down to below 3.5fps with my older Sandisk Ultra II 15MB/s 8GB card (Class 2), a lower cost Peak 16GB, and similar Inov8 16GB. Worse than this by far, video shooting was suddenly cut off at unpredictable points – the same card might manage four minutes, then produce an error message that video capture had been ended after 10 seconds.

Sandisk came to the rescue with the latest Class 10 Extreme SD card rated at 30MB/s, and I sent Canon the most unreliable card – the Inov8 – to test. It confirmed that despite the card bench-testing as Class 6 and writing fast for the first four gigabytes or so, the data transfer rate in-camera was unpredictable after this point, and likely to result in terminated video.

After testing half a dozen new and older cards, I concluded that for maximum still shooting rates and for continuous video up to the limit of around 12 minutes (at either 1080p or 720p) the only safe choice would be a Class 10 not Class 6 – and that the 30MB/s Sandisk Extreme SD was the only 100% reliable choice. In theory, a card with just 15MB/s write speed should be sufficient. They are not – the quality of the NAND memory and internal architecture matter. Don’t assume that your existing SD cards, which work fine with still DSLRs or even with digital camcorders, will be adequate with this model.

Focus calibration
Despite the far simpler AF array of the 550D, with its single f/2.8 central sensor, I found it more accurate with everyday subjects than the 7D. The high resolution of the 7D may be more than the supplied 15-85mm and 18-135mm lenses could handle, but both produced very sharp results on the same resolution 550D.

Photographers who only use Canon often say that no one uses autofocus point selection, and Canon cameras need in-depth understanding. But the 550D seems to work right out of the box. Auto nine-point focus point selection (shown in the finder) resulted in perfectly focused subjects exactly where the system indicated it had locked on. Does this mean the AF system of the 550D is superior to the 7D? Maybe Canon has adjusted whatever parameters it can to yield more consistent and acceptable results from the inexperienced user. That must include me, as my hit-rate with the 550D was definitely better than with the 7D.

There could be one other factor. The 7D and higher level pro Canons now all offer micro AF adjustment, programmable for every lens you use. The 550D does not, though the camera firmware includes vignetting correction for identified lenses, and it will have the usual table of lens identities present. The 550D AF calibration may simply be optimised for the kind of wide to tele zoom I used.

Extreme tele effect
One benefit of having 18 megapixels on a 1.6x crop factor sensor is the potential to capture distant subjects. The sensor is 22.3×14.9mm, with 5184×3456 pixels. If that sensor was made for full frame, it would be 8368×5578 pixels, or 47 megapixels. Canon’s highest density full frame sensor (as I write) is 21 megapixels, with 5616×3744 pixels.

That means that using a 300mm lens on this body (or the 7D) is like having an additional 1.5× subject magnification compared to a similar final reproduction size crop from a 1Ds Mk III. That’s 1.7x compared to the 1D Mk IV, or a significant 2.78× compared to the original EOS 300D six megapixel body, which is the 550D’s direct ancestor. Or at least, it is for still photography. But the 550D has a unique video mode for shooting VGA (similar to S-VHS, television standard resolution not HD) using a crop down to the actual 640×480 pixels required.

This 7.2× video is a remarkable function for motion shooters who don’t want HD, but do want extreme reach. Even the 15-85mm becomes equivalent to a 980mm with this enabled. It is not really possible to hand-hold, even with image stabilisation, so a lens like the 15-85mm with mode III image stabilisation (which detects and compensates for tripod use with IS turned on) is desirable. The extremes to which this video crop could go with long lenses must wait to be seen, but early buyers are already hunting down wildlife and other subjects to shoot at 60fps, VGA, and their 500mm f/4 lens becoming the equivalent of a 5760mm or about 0.7° angle of view.

Image quality
Such tele capability is worth little though unless you can use fast shutter speeds in low light. Here, as with the 7D, Canon scores by making the high-density sensor very clean at high ISO settings. The arrival of Adobe Photoshop Lightroom 3 Beta v2 during my test period improved things further.

The highest official ISO setting, 6400, produced amazingly smooth low noise images in outdoor low light conditions when processed using the new Lightroom 3 noise reduction and sharpening tools. The results rank alongside the Nikon D3s and Canon EOS 1D Mk IV, which don’t seem to be improved to the same extent by the Lightroom upgrade. They are far superior to the EOS 50D, 500D and any previous EOS APS-C model even with much lower pixel densities. The 550D also has better dynamic range, maybe at the expense of some colour discrimination. All this is achieved with the help of gapless micro-lenses and low-density colour filters on the sensor.

Exposure, from the same 63-zone colour sensitive module as the 7D, is linked to focus point in matrix mode and needs similar user control. I rarely needed to override, or to switch to centre-weighted or spot/partial modes. Dust, which could be a menace on 18 megapixels, was not an issue during my test and I didn’t have to remove any spots or clean the sensor. It has a tried and tested sensor cover glass vibration during switch-on, together with anti-static treatment, and this all seems to work well.

Lens choice
Nikon now puts ultrasonic motor focus and image stabilisation into every kit or wide range zoom offered as a kit option. Canon does not. There appear to be three ways to buy the 550D, other than body only. The 18-55mm kit lens has image stabilisation, and you can add a 55-250mm f/4-5.6 IS in a two-lens deal. These lenses use micro-motor focusing. So does the standard wide range kit lens for the 550D, the 18-135mm f/3.5-5.6 IS. IS is vital for video, and after six years of shooting with stabilised systems there is no way I’d revert to using non-IS lenses. But USM focusing is superior, and to get it you have to spend much more.

I tested three Canon kit zooms with the 550D – the 18-135mm (usual choice), 18-200mm f/3.5-5.6 (older design, but likely to be offered as a kit option) and the latest 15-85mm f/3.5-5.6 IS USM. The last lens performed well on the 7D, and it’s in a class above the other two, while offering a better wide-angle extreme than the earlier 17-85mm f/4-5.6 IS USM. It also costs significantly more than the 550D body, and is 50% more than Nikon’s 16-85mm AF-S VR equivalent.

With a lightweight, travel-friendly body, a compact kit lens or a wide range superzoom makes sense. You might not choose either as a professional lens, and many opt for full frame L-series Canon EF lenses even for use on the 1.6x cropped format bodies.

Not surprisingly, my picture tests showed the 15-85mm to be the best performer, followed by the 18-135mm, then the 18-200mm. The 18-135mm is closer to 15-85mm standards than the older 18-200mm. The 18-200mm has the straightest line geometry at 18mm but it isn’t very sharp beyond 50mm and chromatic aberration is strong even when stopped down. The 18-135mm has higher levels of distortion, barrel at 18mm and pincushion at medium settings, but it’s neutral around 22-28mm, low at 135mm and combines high detail sharpness with minimal CA. It feels the smallest of the three, using convenient 67mm filters instead of 72mm, and it weighs least at only 455g.

The 15-85mm has moustache-type distortion at 15mm, eliminated by just shifting the lens off its widest angle. It can show strong CA if bright edges fall in an out of focus area, and the corners are fairly soft wide open at 15mm. The best results are not markedly superior to the much lower cost 18-135mm even though the lens is in a different class for build quality and focus control.

The 18-135mm image stabilisation seems to be optimised for video. The image adjustment is very well damped and the IS mechanism is quiet. It may be the best kit-lens choice for the EOS 550D. Fortunately the little 50mm f/1.8 Canon EF II barely costs three figures and it’s an ideal length for talking heads or interviews.

Conclusions
I haven’t listed all the specifications of the 550D but they are easy to find online and Canon’s site allows you download a PDF copy of the complete instruction manual. Sure, the 550D is still a descendant of the lightweight 300D, with its steel skeleton and GRP skin – it’s a camera built to a size, weight and cost to suit the family and enthusiast market. But it’s also in a class far removed from its ancestor.

Take video work – you can afford three EOS 550D bodies for the price of a single 5D Mk II, and the 550D will shoot video to exactly the same range of US and European industry standards. Three bodies give you multiple camera angles, whether static in unmanned tripod positions, or with human operators. Being able to edit from three simultaneously filmed takes puts you into a different league. For travel photography, or assignments that involve flying (and tight weight limits on checked-in bags), it will also be invaluable because it weighs less than 500g before batteries.

It’s hard to find reasons not to buy a 550D. I’m using the cost of the lenses I want as an excuse but I won’t be able to hold out for long. It does too many things I want that my existing DSLRs don’t do, and it does them well. And at this price, it will pay for itself in a day.