by Ian Burley
E-30 added to DxOMark database
DxOMark is the brainchild of DxO Labs, the Paris-based outfit that serves as an expert consultancy to the imaging industry, as well as producing the retail image optimisation software, DxO Optics Pro. For those interested in the Four Thirds (and Micro Four Thirds) family, the Olympus E-410, E-510, E-420, E-520, E-3, and now the E-30, have all been rated in in the DxOMark database, as have the Panasonic Lumix DMC-L10 and the DMC-G1. The E-30 DxOMark rating, which attempts to give a general guide to the image quality of a camera by technically evaluating a suite of factors from RAW output from the sensor, is slightly lower than the latest generation of 10 megapixel Olympus DSLRs, though slightly higher than the 12MP Micro Four Thirds Panasonic Lumix DMC-G1, which is generally regarded to have exactly the same Panasonic sensor as the G1. It's worth noting that Panasonic uses its own Venus Engine image processor chip, while Olympus has its own TruePic engine.
Just for fun, I've plotted the overall DxOMark ratings for the Four Thirds family cameras that have been rated, plus the DxOMark dynamic range results (in EVs, @ lowest ISO) for the same set of cameras. Also included is one of the best compact cameras, a Canon Powershot G10, to contrast the difference between small sensor compacts and small sensor DSLRs.
I'm tempted to think that the E-3's sensor performance has been specially optimised for maximum available performance, maintaining an edge over the newer E-420 and E-520 models, which have the same basic 10MP sensor. The E-30 rating will probably disappoint many. The optimistic side of me suggests that the extra two million pixels squeezed onto sensor has not been at an an excessive price. The important improvement in high ISO banding issues we've seen in the Lumix G1 and the E-30 are not reflected in the DxOMark ratings. Resolution is not factored in DxOMark ratings either. There is a statistically huge drop to the Canon G10 compact, which should put into perspective the relationship between Four Thirds as the smallest DSLR sensor and even the best compact cameras with their relatively tiny sensors.
Above is the plotted comparison between the dynamic ranges offered by each camera at the lowest ISO available, measured in EVs. Here, the Panasonic Lumix DMC-L10 takes the honours, though the Olympus E-3 maintains its position at the sharp end. And the 12MP E-30 and G1 cameras keep in touch with the second-generation Olympus 10MP models, and comfortably out-perform the first-generation Olympus 10MP models. The Canon G10 compact looks good in this chart, but if you compare its dynamic range across the ISO range, a big gap opens up.
One disappointment with the E-30 is that its claimed ISO speed ratings are now like many of its competitors, rather optimistic. Until recently, most Olympus DSLRs were confirmed as having very accurate ISO calibrations by the DxOMark tests.
The DxOMark ranting also takes into account low light ISO performance and colour sensitivity. I'm interested in the colour depth statistics, because there has been some concern that Olympus and Panasonic have not followed Canon and Nikon into the trendy feature of 14-bit colour processing, from the usual 12-bit processing. As I expected, there is very little measured advantage in colour depth when comparing, say, the 12 bit Olympus E-3 and 14-bit Canon EOS-40D.
Still room for improvement
But Panasonic still has work to do. Canon's 15MP sensor in the EOS-50D has the same pixel pitch as the 12MP Panasonic sensor in the Olympus E-30, but delivers significantly better dynamic range and high ISO performance. Again, I see this as positive - if Canon can do it, Panasonic will probably get there eventually. Panasonic already says that their latest sensor in the Lumix GH1 has improved high ISO performance and dynamic range over the G1, and that can only be encouraging news for Four Thirds overall.
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