For such a small size, the A7SII really packs a punch when it comes to video. Although essentially built for photography, we'll sum up the basics of turning this small beast into a movie making machine.
1. Go manual
When shooting video, conditions often change: your subject moves around, light changes, color temperature shifts. While the A7SII is pretty capable of adapting to all these circumstances, you don't what it to start looking for new settings while you're making a shot. So set the camera to manual mode by deselecting all AUTO-options (ISO, ''Movie/HFR', White Balance) in the camera menu.
2. Choose XAVC S as file format
On the A7s you can choose from 3 different file formats. XAVC S, AVCHD and MP4. XAVC S will give you the best results at the highest bitrate. This higher bitrate does require a fast SD card, but it will give you most quality and options in post-production. If you want to shoot 4K, XAVC S is the only selectable file format. In the record setting, select a setting that has 100M. Because at 100 Megabits per second, you will get the least compression out of the camera when shooting internally.
3. Shoot in S-Log or Cine2,3,4
The A7SII can shoot at a higher dynamic range in both Slog2 and Slog3 color spaces. Essentially the sensor will record much more color and contrast than can be viewed by a standard monitor, giving you a lot more to work with in post-production. You'll be able to color grade your footage to a much higher level, and bring back information from the shadows and highlights. To select Slog, go to the menu and select the first tab (with the camera icon). Move the fifth menu screen and select 'Picture Profile'. You can find Slog2 on 'PP7'.
However, with Slog2 or 3 that you can't access lower ISO settings. If you want access to these, go back to your PP7 profile and change 'Gamma' from Slog tot Cine2 (or 3 or 4). You'll still get a fair amount of dynamic range. But note that the setting the camera to Slog and shooting at a base of 1250 ISO, you'll get much crispier footage and less noise.
Ignore the exposure meter when shooting Slog
When you're shooting, you can see a small exposure meter at the bottom of the LCD screen. Usually, this meter is very useful, since it tells you if your footage is over- or underexposed. But when shooting Slog2 of Slog3, your footage will look washed out (because of the bigger color space and high dynamic range). Unfortunately, the exposure meter ignores this setting, so it will just give false results. The simplest way to monitor your exposure, is to simpy look at your histogram.
4. Stabilize your camera
The small size of the A7SII can be great. You can mount the camera in tight spaces inaccessible to regular cameras. However, if you are going to shoot handheld, the light weight of the camera will actually make your footage look overly shaky. With handheld camera work, weight is actually a factor. It will make your camera movements look more smooth and your viewer will suffer less sea-sickness when wachting your work. So when using the A7SII, at least mount it onto a shoulder rig, giving you more control over camera movement. Otherwise, keep it on a tripod.