Local CTF refinement (actions on particles) query

CTF Refinement
1

Hi team,

Does Local CTF refinement do per-particle astigmatism refinement as well as defocus refinement?

Asking because I’ve got a dataset which hits 2.35 Ang in both RELION and CryoSPARC, and with just per-particle defocus refinement reaches 2.25 Ang (in RELION) and the same with Local CTF refinement in CryoSPARC, but with per-particle astigmatism refinement as well in RELION will exceed 2 Ang, and I’m trying to track down why there would be such a large disparity.

Thanks. :slight_smile:

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I’m pretty sure it doesn’t - should be easy enough to check if you convert to star (or I guess you could check it using subset particles by statistic with a one mic selection)

Would be useful to have more options for local CTF refinement - and more flexibility with which parameters are refined with which set of exposure groups

(out of interest - looking at this paper - I wonder if you see a correlation between the per particle defocus and the per particle astigmatism differences?)

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If not, that explains some other things I’ve been seeing as well, then.

Thanks for the paper link also; hadn’t spotted that one.

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