SONY FX6 and FX3
DUAL BASE ISO
When shooting with S-Log3 the two base ISO’s of the FX6 and FX3 are 800 and 12,800.
Why is “Base ISO” so important?
’Base ISO is important because the base ISO normally represents the optimum settings for a video camera. It is normally the point where no unnecessary gain is added to the sensor’s output and it’s the level where the camera is able to record the greatest possible dynamic range.
So, when you are shooting with S-Log or with raw you will almost always want to operate the camera at its base ISO in order to maximize the dynamic range that can be recorded and to record with the lowest possible amount of noise and grain.
The Sony FX3 and FX6 have a dual base sensitivity function that provides two very different sensitivity levels with only a very small noise and dynamic range difference between each.
When shooting with S-Log3 the two base ISO’s of the FX6 and FX3 are 800 and 12,800. This is a huge four stop or 16-times change in sensitivity.
The ability to switch to a more sensitive base ISO without an appreciable noise penalty greatly increases the versatility of these cameras. Now you can shoot high quality content in both bright and dark environments. It allows you to use lower overall light levels if you chose.
If you are using an FX6 (or FX9 or VENICE) and you find that using the high base sensitivity mode makes the camera too sensitive, then you can make use of the built-in ND filters to achieve a lower equivalent ISO. For example, 12,800 ISO + 1/4 ND (-2 stops) will give you the equivalent of 3200 ISO.
(Also it’s worth noting that if you use the camera in gain mode rather than ISO mode that 0dB gain will always be the base sensitivity. So if you can’t remember what the base ISO sensitivity for a particular gamma curve is, consider using gain and 0dB instead.)’
Read full notes at: What is Dual Base ISO? | Sony Cine
SONY FX6
Here are some links to tutorials and tips for using Sony FX6
SONY FX3
SONY FS7