DxOMark have just finished testing the Panasonic GH4 (or rather, its sensor,) and their results are hardly surprising. As it turns out, the GH4 is the best Micro Four Thirds camera currently available when it comes to pure sensor performance. With a total score of 74, it is three points ahead of its predecessor, the GH3, and even outperforms the acclaimed Olympus OM-D E-M1 by one point.
Further analysis is after the jump.
Compared to the GH3, its immediate predecessor, the GH4 scored better in almost all regards, except–and this is interesting–in the low light ISO score. Here, the GH3 set the benchmark with 812 points, and the GH4 only got 791 points. However, when looking at the signal-to-noise ratio measurements for the two cameras, the curves are an exact match.
The only real explanation we have for the different scores is that the GH4’s measured ISO values are actually 1/3rd stop lower than the GH3’s, except for ISO 12.800 and up which is in fact 2/3rds higher. So apparently, Panasonic calculated the nominal ISO values of the GH4 differently from those of the GH3. For practical application, though, this probably doesn’t mean anything.
Compared to the OM-D E-M1, the GH4 is only slightly ahead in most overall scores. It has a minimal edge in signal-to-noise ratio, but in the dynamic range and color sensitivity measurements, the E-M1 is slightly ahead of the GH4 (mind that the scores in these categories reflect the single highest measurement, not the overall average.) Again, for practical application this probably doesn’t mean a lot.
So, what do we learn from this? For one, DxOMark has a unique way to measure the performance of a camera’s sensor, and its scores do not necesarily reflect the real-life performance of that camera. They do give a rough guideline though about the overall image quality. In the end though, as we’ve seen, the differences between most current camera models of the same format are slim at best.
Which means that no matter which Micro Four Thirds camera you’re going to buy, you’ll end up with a more than capable shooter.