mne.filter.notch_filter default notch_widths too low?

[SophieHerbst]

Hello,
when applying a notch filter to EEG data without setting the notch width (stop band width), the default is frequencies / 200. For typical 50 Hz line noise, this results in 0.25 Hz, which appears very narrow. The attached plot shows that the result is not satisfactory.
I think it would be better to set a fixed band width, e.g. 1 Hz for all frequencies.
What do you think?
Sophie

[larsoner]

Yeah that probably is too narrow. It would probably be an annoying deprecation but probably worth it. I think so far I always set it to something else because the default is not good enough