Silvercrest SAK 4000 A1 Operation And Safety Notes page 66

Setting option Function
66 GB/IE/NI
The lower ISO values (50, 100, 200) mean
that the sensor is less light sensitive and are
suitable for shooting in an environment with
good light conditions e.g. in sunny weather.
ISO values from 400 to 800 are suitable for
indoor shots or outdoor shots when the sky is
overcast.
An ISO value of 1600 should be used in very
poor light conditions (e.g. at events, concerts etc.).
Note: The higher the set ISO value, the more
sensitively the sensor reacts to the occurring light.
An ISO value that is set very high can lead to
increased image noise and have a negative
impact on the picture quality. Set the ISO value
as low as is possible in the shooting conditions.