When extracting particles, RELION 3 does not by default write an amplitude contrast column to the star file. (I can’t recall whether RELION 2 did so)
When importing such a file into cryosparc v2, cryosparc opts not to read any of the CTF parameters unless the user manually specifies the AC (meaning that subsequent jobs based on these particles fail, complaining that no CTF blob is connected).
Would it be possible to have v2 default to assuming AC=0.07 (or 0.1), if no value is present in the input? Purely for convenience this would be useful, I think.