So which camera is the resolution king?

Do you need more pixels for maximum resolution?

12 megapixels of Olympus E-5 versus 16 megapixels of Panasonic GH2

Although Olympus has exclusively used LiveMOS sensors made by Panasonic since the E-330 in 2006, Panasonic's implementation of the same sensors in its Lumix L10 Four Thirds DSLR and G-series Micro Four Thirds hybrid cameras has incorporated one significant difference; a less powerful low pass filter. This is a filter that deliberately blurs the image projected by the lens onto the sensor.Why would you want to introduce blur? Well, without this filter there would be noticeable jagginess or 'aliasing' of sharp edges and pronounced moiré in some areas made up of fine regular details. Moiré results in interference patterns and even some localised colour distortions.

Olympus' philosophy had been to produced smooth details, sacrificing resolution, by using a strong low pass filter. But that all changed recently, since Olympus started to produce its Pen range of Micro Four Thirds cameras. Olympus clearly endowed the Pens with a less strong low pass filter, emulating the policy already established by Panasonic. When Olympus revealed the E-5, we discovered its low pass filter was weaker still. With its very weak low pass filter the E-5 produces noticeably more detailed images. There is no evidence that this has been at the cost of noticeable moiré or aliasing in general photographic imagery.

At the same time Olympus started to ship the 12 megapixel E-5, Panasonic was preparing to release its Lumix DMC-GH2. With a unique 16 megapixel LiveMOS sensor, surely the GH2 would be the resolution king among Four Thirds and Micro Four Thirds cameras? Actually, no; the E-5's weak low pass filter actually enables the camera to resolve more detail than the GH2 despite depending on just 75% of the pixels that the GH2 is endowed with:

In our tests the results (above) clearly show that the E-5 and GH2 can significantly out-resolve Olympus' E-3 and E-30 DSLRs. The E-5 also out-resolves the GH2 at low and high ISO settings, although the GH2 rallies in mid-range ISO sensitivities.

Admittedly, the E-5 test charts showed aliasing and moiré was present, as it was, incidentally, with the GH2. But the test chart is not a typical photographic subject and maybe Olympus gamble of severely reducing the power of tech E-5's low pass filter has paid off.


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