Choosing the best "base_log" and "level" parameters in Bootstrap Key

Hi Community,

I am using an older version of concrete library (version 0.1.11) for one of my projects. For the project I have to apply bootstrapping to compute value of function in encrypted domain using PBS. I am unable to understand how should I choose the base_log and level values for the bootstrapping key. Is it dependent on the Encoder precision and padding bit?

If so, how should I set it?

Thank you in advance for the help