I remember attending the launch of the Four-Thirds system at the Photokina camera show in 2002, where Olympus claimed that a fully integrated digital system had many advantages over the more organic developments of the competitors. At the time it made a lot of sense and many of the innovations Olympus developed have since been incorporated into other manufacturers' models (despite their scepticism and derision at the time!).
The major claim though was an improvement in image quality. However we have yet to see any major improvement, and certainly in the case of image noise Olympus has struggled to reach the high ISO performances of, other manufacturers such as Nikon or Canon.
This continues with the images from the E-420, which have good noise control at the lower ranges of the sensitivity, but problems increase as the gain is raised. I wouldn't say the noise is terrible but it is visible, and has a granular texture that some photographers may like. Chroma noise is maintained at a similar level throughout the colour channels, so I'd say it's well controlled. It's just a shame Olympus can't match the higher ISO ranges of some of its rivals.
One area in which the Olympus E-420 excels is detail management. Images are smooth and detailed, with very good sharpness, even with the basic kit lens, and very little sharpness fall off at the corners is evident. Similarly there's no sign of vignetting.
Exposures are generally good, though slightly underexposed. This maintains good highlight detail, but means for the perfectionist a certain level of post processing is required to bring the images up to par. For the average user, whom this camera is really aimed at, it's good enough for general snapshots and experience will allow them to learn thanks to the cameras more advanced exposure features.
There's very little to criticise in the overall specification and performance of the E-420. I like it's size - it's ideal for travelling and is reminiscent of my old OM4 in some aspects of its handling.
Images are generally good too, with excellent sharpness and detail. Colour is crisp and while exposures are slightly underexposed to my taste, they do maintain good tonality throughout the range.
The Four-Thirds system is somewhat contentious amongst the more vocal geeks on the forums, but it has many benefits and is definitely worthy of consideration to anyone coming to a DSLR for the first time. The Olympus E-420 is a pleasure to use and it's simplicity combined with the more advanced features allows the newbie to learn and grow as well as just enjoying taking good images.