DxOMark suggest Four Thirds sensor technology has made a big leap in performance

Could the Four Thirds Achilles Heel soon be consigned to history?


Is the Panasonic Lumix GH1's LiveMOS sensor as good as the best APS-C sensors?

If there is one factor that has prevented the Four Thirds DSLR platform from enjoying more success than it has managed to achieve, it's probably the availability of very high quality image sensors. This has nothing to do with the slightly smaller than average dimensions of the Four Thirds sensor. It's more to with the fact that Olympus and, latterly, Panasonic, have not had access to the high quality range of sensors, enjoyed by all their rivals, produced by Sony and Canon. According to this week, Four Thirds has now achieved parity with the best rival sensor technology, at last.

First of all, here is a brief history of Four Thirds sensor. In 2003 the Olympus E-1, the first Four Thirds system camera, was launched. It featured a Kodak full frame transfer (FFT) CCD sensor. many still regard this sensor as a highlight of Four Thirds because of its excellent colour reproduction, but there is no getting away from the fact that it was noisy at even moderate ISO levels. The same Kodak FFT sensor technology was scaled to from 5 megapixels to 8 megapixels through the E-300, and E-500 DSLR models. The E-400 employed a Kodak interline transfer CCD sensor, and that was the end of Kodak's contribution to Four Thirds. Panasonic replaced Kodak as the exclusive supplier of sensors, trademarked by Olympus as 'LiveMOS' sensors. Although Panasonic was an experienced manufacturer of CCD sensors in its own right, its own technology - a close relative of CMOS (already popular is a replacement for CCD with other DSLR manufacturers) was at least two years behind the competition when the first Four Thirds LiveMOS sensor, a 7.5 megapixel part, was featured in the Olympus E-330, and shortly after in the first Panasonic DSLR, the Lumix DMC-L1.

There have been at least three generations of LiveMOS sensor since, each bringing modest improvements in noise and dynamic range performance, despite creeping up to 12 megapixels. But it's the LiveMOS sensor exclusive to the Panasonic Lumix DMC-GH1 Micro Four Thirds camera that has broken into the top tier of 'small' sensor DSLR performance category. recently tested the RAW image file performance of the GH1 and discovered that its noise, dynamic range, and colour reproduction performance was significantly better than any previous LiveMOS sensor. Pixel for pixel, DxOMark rates the GH1's sensor at the same level as the 18 megapixel APS-C CMOS sensor of the Canon EOS-7D. This is interesting because the pixel densities of these two sensors is very similar. It suggests that Panasonic has at last caught up with its rivals in sensor technology terms and this is great news for the future Four Thirds, and Micro Four Thirds.

There have been many rumours that Panasonic is stepping up its sensor technology this year. The Lumix GH1 was launched in September last year, and several Micro Four Thirds models from Olympus and Panasonic have arrived since, but they all use the previous generation of LiveMOS sensor. The expectation is that another new generation of LiveMOS sensor will be unveiled by Panasonic later this year, perhaps employing the so-called back-lit style of sensor to further optimise the efficiency of the light gathering function of the sensor.

In the mean time, if you want the best sensor yet for a (Micro) Four Thirds camera, the Panasonic Lumix DMC-GH1 is the camera to go for.

Read the article on the Panasonic Lumix DMC-GH1's LiveMOS sensor.

Read my article explaining some other unique properties of the Panasonic Lumix DMC-GH1's LiveMOS sensor.


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