In the film days, I would shoot tests on new film stocks to determine how the negative responded at various levels of over and under exposure. Think of it as establishing the usable or practical dynamic range of a particular film stock. Those tests were my guide to the pre-visualization of my lighting — which areas of a scene would be lit at the stop I had chosen for the scene and which areas should be under or over exposed and by how much.
Although digital images can be evaluated in real time, I still use incident and spot meters. I conducted this Panasonic Lumix GH5 dynamic range test to evaluate how the sensor responds as it is over and under exposed. I used the well known X-Rite ColorChecker Video chart.
I don’t shoot log at this point so I used my usual settings.
ISO: 400
Rec Quality: 4K, ALL-I, 400M, 24P
Photo Style: Natural - Contrast, Sharpness, Noise Reduc., Saturation, Hue settings @ 0
Luminance: 64-1023
Lens: Voigtlander 42.5mm f/.95 Nokton
Light Source: 5600K
Color Balance was set using a Lastolite EzyBalance Gray Card. Color temperature was checked at each light level change and varied no more than 50 degrees kelvin from the 5600 degrees kelvin baseline.
UHD files were imported into Premiere and trimmed to approximately 5 seconds for the slates and 15 seconds for each exposure. No correction was applied to color, contrast or exposure. The over and under timelines were output as 1920 X1080 MP4 files.
I managed to shoot the +2 2/3 EV twice — thus leaving out the +2 1/3 EV. Also, there is a noticeable reflection of the left light on the darkest wide strip at the bottom.
GH5 Normal to 5 Stops Over
GH5 Normal to 6 Stops Under