Exposure Latitude

In this test we look to see how tolerant of pushing exposure the G85's Raw files are. We've done this by exposing our scene with increasingly lower exposures, then pushed them back to the correct brightness using Adobe Camera Raw. Examining what happens in the shadows allows you to assess the exposure latitude (essentially the dynamic range) of the Raw files.

Because the changes in noise are primarily caused by shot noise and this is mainly determined by the amount of light the camera has had access to, the results are only directly comparable between cameras of the same sensor size. However, in real-world shooting situations you may well be limited by what shutter speed you can use, so this test gives you an idea of the amount of processing latitude different formats give.

Based on our test results the G85 offers nearly identical exposure latitude to the Panasonic G7 as well as the Olympus OM-D E-M5 II. This means you can expect similar degree of processing flexibility from Raw files.

ISO Invariance

A camera with high (base ISO) dynamic range has a very low noise floor, which has an interesting implication: the low noise floor reduces the need to amplify the sensor's signal in order to keep it above this floor. This can afford you benefits in situations conventionally demanding higher ISO settings: you can use a lower ISO and push the Raw files, rather than applying hardware amplification and clipping lots of highlight data.

Here we've done something that may seem counter-intuitive: we've used the same aperture and shutter speed at different ISO settings to see how much difference there is between shooting at a particular ISO setting (and using hardware amplification) or digitally correcting the brightness, later.

With the G85, there is nearly no difference in noise performance between shooting at ISO 1600 vs. using the same exposure with the ISO knocked down to 200 and pushing the file 3EV in 'post', suggesting the camera is adding very little noise. This is assuming you are using the mechanical or electronic first curtain shutter mode as opposed to the E-shutter which knocks the bit rate from 14-bit to 12-bit.

By underexposing 3EV, users can avoid over-amplifying the top 3EV of highlight information and blowing it out. These results are nearly the same as what we observed with the Panasonic G7 and Olympus OM-D E-M5 II.