If the transition from the EOS 300D to the EOS 350D was easily noticeable (tighter camera body and better finishing touches), the natural evolution to the EOS 400D is a lot less obvious. You will have to look internally at the new technology (dust reduction system) to see the entire potential of this new Canon reflex.

Without being an all out revolution (like it was with the 300D in 2003), the 400D integrates small very appreciable improvements. The first is the transition to a CMOS 10 million pixel sensor. Images in 3888 x 2592 pixels offer a large quantity of content and superb color rendering. The increase in the number of pixels could have spelled bad results in terms of noise, but this isn’t the case here. And to the contrary, this new family of sensors offers much higher performance and the processing of data by Canon’s own processor (the Digic II) makes miracles. Photos are easily usable up until 800 ISO and even 1600 ISO if we take the time to touch them up with specialized software afterwards.  As image files are heavier, it would be only normal to expect the camera to be slower. Here again, Canon comes through and the EOS 400D is extremely reactive from startup to burst mode. Canon is true to their technical sheet and the 3 images/s for 25 shots is respected.

On the other hand, there was little evolution for the (rechargeable) battery, but it gives us up to 500 images and this means we can leave for the weekend without looking for a power source. In addition, thanks to the display of parameters on the large LCD screen, the 400D’s interface is more practical. But the biggest innovation is the new dust removal system via low-pass filter vibrations in front of the sensor.   This is a functionality that has been awaited by photographers owning several lenses and by professionals.

The anti-dust system which is "in test" on the 400D should quickly become available on the Canon line and why not on high end models. Besides eliminating dust, this system proposes a nice (and more efficient) alternative to manual cleaning which is a long and delicate process.  In the field or in action, photographers will appreciate the result.

Obviously, everything isn’t perfect on the 400D, starting with the viewfinder which is too narrow - almost a keyhole. We also would have liked to have seen a second adjustment dial to facilitate use in M mode. Likewise there no mechanical stabilization on the sensor. A propos, the presence of stabilized lenses (rather expensive) in Canon’s catalogue will limit (or stop) the appearance of this technology on its reflexes.

So should Canon fans crack for the 400D? While the anti-dust system is a real plus, the other innovations (autofocus, 10 million pixel sensor, and larger LCD screen) are less "essential" for the amateur photographer. Compared to the 300D, the gain is really noticeable. But the 350D, a very nice final product, can actually compete with the 400D! Buying a 350D, which is less expensive, will allow you to obtain a better quality lens like the 24-135 mm IS (stabilized) or the Sigma 17-70 mm for less. This is something that should be taken into consideration. And as the stock of 350Ds won’t last forever, keeping an eye out for current deals could be an option.

Strategically, Canon has made the 400D the least expensive deca-megapixel on the market, a position that was tried and true with the 350D. The inexpensive, small and high performance EOS 400D is intended for the beginning photographer and true Canon follower. However, compared to the competition, the 400D struggles. It’s true that the Nikon D80 doesn’t have dust reduction, but its body is more reassuring, the viewfinder is clear and precise, and the versatile 18-135 mm lens looks more attractive overall. 

Finally, there is Sony’s Alpha 100 which is technologically complete with mechanical stabilization, an anti-dust system, nice interface, and 18-70 mm zoom. It’s a serious competitor, which thanks to a few details (possibility of use with Zeiss lenses, numeric flash and wireless flash) wins our preference compared to the Canon 400D.