How to limit initial filtering of reference map

Hello,
I am working on a small membrane protein and it is known that for small proteins if one filter the initial reference to 30 angstrom, it is unlikely to reach high resolution so, I want to limit initial filtering to 8 or 10 angstrom. Is there a way to limit this as I cannot see any option in homogeneous or heterogeneous refinements?

Thank you.
Gaya

Hi Gaya,

Switch on Advanced Mode, then you will see it. Be cautious about starting at too high resolution though, and be even more cautious if not staring from an ab-initio model!

Oli

Thank you Oli,
We have very good ref map generated in Relion and cisTEM and want to use that for cryoSPARC.

Thank you
Gaya

Good luck! I would just be cautious in limiting lowpass filtering - you shouldn’t normally need to alter this too much, and I would certainly not advise going to 8-10Å. Do you not get good results with the default value?

Heterogeneous refinement looks okay but when I tried to do Homologous refinement it mess up the corrected FSC.

What might be wrong? Should I do more heterogeneous refinement to separate out more particles that might not belongs to that class average?

can you post a snapshot of the FSC?