by Ian Burley
DxOMark reveals that the Pen E-P3's LiveMOS sensor is not as new as it would seem
There has been much speculation about the new 12 megapixel LiveMOS sensor used by Olympus in the new Pens that were revealed late last month. It's definitely new - it has a doubled frame read out speed (from 60 frames per second to 120 fps), which enables smoother live view and faster autofocus. Indeed, the new sensor has enabled Olympus to claim that the new Pens can focus faster than any other camera, including DSLRs, at the time of writing. And we have seen from actual image comparisons that there is a significant improvement in visual image quality from camera JPEGs compared to previous generations of Micro Four Thirds cameras. With news that Panasonic, with the new Lumix DMC-G3, has demonstrated that the LiveMOS Four Thirds format sensor can be scaled from 12 to 16 megapixels without sacrificing noise and dynamic range, there was hope and expectation that the same sensor hardware improvements could be applied to a new 12 megapixel LiveMOS sensor that would result in a measurable improvement in RAW-level performance. So, do the new Pens have such a new next-generation LiveMOS sensor? That question will be answered a little further down the page, but first, let's look at how the E-P3 compares to the old E-P2 and the even older Panasonic Lumix DMC-G1, which launched Micro Four Thirds back in September 2008:
The charts below measure luminance noise (image grain) throughout the camera's ISO range. The test images are machine-read and results calculated using DxO Analyzer 4.0, the image quality test suite we use in-house. As none of the RAW converters we use are yet tuned to work with E-P3 RAW files, the noise evaluations were made using in-camera JPEG images. We used two settings, the first chart shows the results when the cameras' noise filters and sharpening settings were set to minimum or off. This effectively minimises the effect of in-camera image processing. The second chart shows the results when the camera settings are set to standard. The measured result is in dB and the higher the number the better.
Across the board the E-P3 shows a healthy advantage over the older cameras. In fact its advantage is even higher than the charts suggest because, with the G1 especially, chroma noise and other artefacts at high ISO like pixel clumping and colour blotching is much more evident on the older cameras. Our image noise comparison article featuring the same set of cameras suggests that at ISO 3200 the E-P3 has about a two thirds EV advantage over the old E-P2 and at least 1 EV advantage over the G1.
But is this enough evidence to confirm that the E-P3 has a sensor with better basic image quality? Unfortunately, the first authoritative evidence based on measurements of RAW sensor data from the E-P3 firmly points the the E-P3 sensor being exactly the same as previous Pens and other 12MP Lumix Micro Four Thirds models. This data comes from DxOMark, the same people that produce the DxO Analyzer software we use here for testing at Four Thirds User, and the excellent commercial DxO Optics Pro image processing software. See for yourself.
So where is the distinct improvement in E-P3 JPEG image quality coming from? It's all down to the latest Olympus TruePic VI image processing engine, which is responsible for creating in-camera JPEG images, among other things. TruePic VI now has two processor cores so the live view processing and other functions not related to image quality don't drain processing power. With more horse power for image processing, plus the inclusion of detail retention technology first seen in the Olympus E-5 DSLR, E-P3 in-camera JPEGs are better than ever.
So where does that leave those of us, me included, who prefer to use RAW images? Sadly, if you are looking for improved dynamic range or noise performance, it's unlikely you will get any once your favoured RAW processor supports E-P3 RAW files. Compared to older cameras you will hopefully see a boost in detail resolution thanks to am E-5 style weaker anti-aliasing filter, but that may be all the improvement you can expect. An update to Olympus' Viewer 2 software, which includes RAW processing, is due very shortly, and the big names in RAW conversion, like Adobe, should be adding E-P2 RAW compatibility in due course.
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