FSC-mask auto-tightening

Features and Functionality
1

I found after FSC-mask auto-tightening, the resolution is improved a little bit.
I am wondering how cryoSPARC does the “auto-tightening”.
btw: should we report the FSC before or after the “auto-tightening”?
Thank,
Lei

2

Hi @rainfieldcn,

The FSC auto-tightening is based on noise-substitution correction (see https://doi.org/10.1016/j.ultramic.2013.06.004
for reference) for gold-standard FSC. Essentially, the FSC mask is tightened as far as it can be before the noise-sub corrected FSC starts to differ from the masked FSC. If the noise-sub and masked FSC are different, this indicates that the mask is too tight. So the mask is tightened as far as possible before this happens. This is typically the process that users of other software packages perform manually after a refinement. I would suggest that you report the FSC after auto-tightening.

Ali

3