From the EOS 10D to the EOS 20D, then to the current EOS 30D, Canon has adopted the "if it ain't broke, don't fix it" approach for its midrange digital SLRs. Aside from better performance compared with its award-winning sibling (EOS 20D), the 30D is largely similar to its predecessor. Canon has also added some feature upgrades, for instance, a larger LCD monitor, spot metering, Picture Styles and a selectable continuous shooting speed to pull it further ahead of the 20D.

What's new
In terms of design and layout, the differences between the 20D and the 30D are miniscule. The front of the handgrip, just above your middle digit when holding the unit, now has a little protruding "lip" which prevents your finger from slipping upwards. We also welcome the larger 230k-pixel 2.5-inch LCD monitor which has replaced the 1.8-inch screen on the 20D. Pity, though, that the screen isn't coated with an anti-reflection layer.

Canon proves that it has been listening with the 30D. One of the much-awaited improvements in the features is the inclusion of the spot metering option which, according to the company, covers approximately 3.5 percent of the viewfinder.

Picture Styles, which was first introduced on the EOS 1D Mark II N and subsequently implemented on the EOS 5D, appears on the current EOS 30D as well. What this feature does is allow the user to preset certain image parameters, such as, sharpness, contrast, saturation and color tone, to suit various shooting conditions. At the same time, it gives the photographer a greater degree of control over how the images will turn out.

The inclusion of two continuous shooting modes, compared with the fixed 5fps on the 20D, is also a pleasing enhancement on the 30D. Users can now select between a high-speed 5fps and a low-speed 3fps setting. There's also a noticeable improvement in the buffering on the EOS 30D. The camera is capable of capturing 30 JPEGs in Large/Fine quality (20 on the 20D) and 11 RAW images (six on the 20D) at a burst.

In use
Canon's EOS 30D, like the 20D, keeps most of the digital EOS design traits. In our hands, the magnesium-alloy body feels well-balanced and rugged, yet does not undermine portability. The 30D is merely 2mm thicker at 144 x 105.5 x 73.5mm than its predecessor and the body weighs only 15g heavier than the 20D (685g).

The viewfinder, though it displays only 95 percent of the actual scene, is bright and easy to check for focusing. Since the 30D shares the same sensor and imaging processor as its predecessor, you can expect similar high-quality pictures, especially at high sensitivity levels, and top-notch performance.

Like the 20D, the 30D is compatible with a whole range of EF/EF-S lenses. In addition, the 8.2-megapixel APS-C-sized CMOS sensor has a 1.6x crop factor, which means that an image taken at 18mm has, in fact, a field-of-view of 28mm (35mm equivalent).

In terms of performance and speed, the 30D certainly doesn't disappoint. Even when the camera is turned off, it doesn't totally switch off; it's more as if the shooter is in a dormant mode. For instance, when you insert a CompactFlash card into the unit while the camera is off, the red indicator light lights up showing that the shooter is reading the card.

Because of its "never-really-off" status, the 30D reported for duty almost instantaneously in our tests. Autofocus timing was also good and we could use either the multi-controller or the circular dial to select the AF points arranged in a nine-point diamond formation. On our 1GB Imation CompactFlash test card, we managed to clock 12 pictures in RAW before the buffer filled up.

One quibble we had with the 30D was that the camera would shut down when the CompactFlash compartment door was opened. Generally, this meant that any images yet to be written onto the card (in other words, still in the buffer) would be lost. We would also have liked to see the ISO setting on the top LCD panel instead of having to press the Drive/ISO button to know which ISO the camera was currently on.

Conclusion
Those looking for premium alternatives may want to train their eyes on the pricier midrange dSLRS like the EOS 5D and the Nikon D200. For a lot more money, you get a 12.8-megapixel EOS 5D with a full frame (often referred to as the Holy Grail of digital SLR technology), 23.9 x 35.8mm CMOS sensor. In short, Canon's EOS 5D's design and performance are unexceptional, but its high-resolution images offer superb detail, rich tonality, and incredibly low noise.

Nikon's D200 seems like a closer competitor, both in terms of technical specifications and price, to the EOS 30D. So while the D200 is a significant step up from the entry-level to midrange D50 and D70s shooters, its main lead over the 30D lies in just the two extra megapixels. The D200 also betters the EOS in other less significant areas like having a dedicated built-in flash assist lamp unlike the latter's pop-up flash which doubles as the AF illuminator and has to be manually flipped up to activate. Even though the D200 appears to be slightly more versatile, the choice of dSLRs boils down to individual preferences.

Building on the merits of the 20D, there is no doubt that the 30D is also a performer. However, current 20D users may find it less convincing to cough out the cash differences for a nominal improvement in terms of features, unless they absolutely need a spot metering option, larger LCD and more control in how their pictures turn out with Picture Styles. Despite the limited reasons to upgrade, the EOS 30D is still able to hold its own with the competition and will appeal strongly to enthusiasts or first-time digital SLR buyers.