Shooting in low light with modern video cameras is often challenging and a recent shoot at the Chinese New Year lion dance at Bristol's Wapping Wharf was no exception.
We usually use our main Sony Fs7 camera in the flat profile Cine EI SLog3 mode, which is fantastic for daylight filming due to its massive 14 stop dynamic range. The downside is that the native ISO of 2,000 is unchangeable and when it gets dark and the aperture is fully open, you sometimes just need a bit more brightness...
With this in mind, we tend to shoot dark sequences on the Fs7 in Custom mode instead, with a gamma of HG3 or HG4. As well as giving a fantastic look to the (essentially already graded) footage, you can add as much extra gain / ISO as required, with practically no picture noise. On this front, I'm a big fan of the Fs7's in-camera noise suppression feature, leaving it permanently at the high setting. If any noise still gets through, Neat Video's third party plugin for Premiere Pro is excellent.
So much for the main camera. For the gimbal shots (our excellent Zhiyun Crane 2) we used the Sony A7s2 dslr.
The two cameras complement each other well. The A7s2 is much smaller than the Fs7 and makes the gimbal rig light and easy to handle. The images match up nicely in the edit with a bit of tinkering. The 8-bit video A7s2 image quality is not quite as good as the 10-bit Fs7 but it's pretty close, as long as you don't push the grading too much.
The big plus though is that the A7s2 is designed specifically for low light performance and it's truly exceptional in this area. Native ISO is 1,600 but it operates happily way higher than that. Exactly how high depends on your view of how much picture noise is acceptable but talk of 100,000 ISO plus is not uncommon.
Cameraman / blogger Philip Bloom has an interesting A7s2 / GH5 low light field test here which is worth a look and shows just how well you can shoot literally in the dark with this camera. As an aside, I understand the much of the recent BBC hit Blue Planet 2's low light ocean deep footage was shot at high ISO on the Sony A7s2, performing better than other much more expensive 'low light' cameras lined up alongside.
I certainly have never had to go super high with the ISO but what I do regularly with the A7s2 is to crank up the ISO to between 5,000 and 10,000 in order to operate comfortably in those all-too-common low light filming situations.
In our case, that might be a dark university laboratory or lecture room (the University of Bristol Wills Great Hall on a dark winter evening...), a night time Chinese Lion Dance performance or maybe the gloomy engine room of a Trinity House ship. These are scenarios where I want to be at F5 or higher to ensure a reasonable depth of field for either gimbal video work or hand-held at 1/150 shutter speed shooting stills.
The low-light capability of the A7s2 makes it all possible.