We were curious to compare the sensors of both the GX7 and the Olympus OM-D E-M1. Both models have a L-MOS type sensor with the same pixel count (16-Mpix), but the E-M1 is known not to adopt an optical low pass (AA) filter that should, potentially, deliver higher sharpness. Our DxOMark sensor performance tests don’t include perceived sharpness results as the optical system is incomplete, instead we must rely on our DxOMark lens tests for that.
We were intrigued to see just how well the cameras performed with the Olympus 75mm f1.8 lens. As the highest performing model in our database, it’s the most likely to reveal any differences in the perceived sharpness of the two systems.
The difference measured in P-Mpix in our Lens metric scores reveals the OM-D E-M1 sensor is potentially capable of higher sharpness than the unit found in GX7. With the 75mm f1.8 mounted, it achieved a higher peak sharpness value of 12P-Mpix, implying an increase of up to 5P-Mpix may be possible by implementing an equivalent sensor without an AA filter.
With those results we were then compelled to test the high-grade Lumix GX Vario 12-35mm f2.8 ASPH. As expected the E-M1 combination did well, achieving an increase of 4P-Mpix over the GX7 with the same lens.
Such big gains aren’t possible with lenses with much lower resolving power. The 14-140mm may be very versatile lens but the peak sharpness was just 6P-Mpix on the OM-D E-M1 dropping to 4P-Mpix on the GX7. Keep in mind however, that while the GX7 appears to have a strong AA filter, the removal in various models may result in color artifacts or moiré and that may also apply to video as much as stills, where it’s very challenging to eliminate completely.
If you have a Panasonic GX7 and a favorite lens, we would very much like to hear from you. Please leave a comment below, stating what lens it is and why you like it.