Why you can trust TechRadar We spend hours testing every product or service we review, so you can be sure you're buying the best. Find out more about how we test.
We shoot a specially designed chart in carefully controlled conditions and the resulting images are analysed using DXO Analyzer software to generate the data to produce the graphs below.
A high signal to noise ratio (SNR) indicates a cleaner and better quality image.
JPEG signal to noise ratio
This graph shows that the GH4 produces JPEG files that compete very well with the other cameras in the group, indicating that images are fairly clean. However, it seems that is at the expense of detail at higher sensitivtiy settings.
Raw signal to noise ratio
The GH4 is the clear winner for raw file (after conversion to TIFF) signal to noise ratio, indicating that noise is controlled well. However, comparing its resolution scores with those of the Fuji X-T1, for example, reveals that it cannot record as much detail at the higher sensitivity settings.
JPEG dynamic range
These results show that the GH4 has a generally high JPEG dynamic range, but there is some variation which may arise from slight changes in image processing.
Raw dynamic range
The GH4's raw files (after conversion to TIFF) are unusually consistent across the sensitivity range. This means that images captured at high sensitivity settings have only slightly fewer tones than those captured at low levels. However, the range of tones in real world images captured at the highest ISO values have a lot of noise which masks the tones and detail.