Running cryosparc without CTF correction

Features and Functionality
1

Hi,

I was wondering if there is any way to force cryosparc to run without having CTF information provided in the initial star file?

Thanks a lot in advance!

2

Hi Rafael,

Currently there isn’t a way to do this. Could you elaborate a bit on the intended use case?

Thanks,
Ali

3

Hi Ali,

I see! Not a big deal anyway. I just found the option would be useful for some cases where I want to run cryosparc with some old data for which I do not have the original micrographs available, but only the stacks of particles (I have both a stack of original particles and a stack of phase flipped particles, but as far as I know cryosparc requires CTF information to be stored in the metadata and not particles that have already been phase flipped). I have forced it to run by giving a dummy value to all the particles, and the overall shape at least looked alright, but I wonder if it could be better if CTF correction was not done (as doing it in this way with wrong parameters is just making things worse probably)

Thanks!

Best wishes,

Rafa

4

Ah, that’s interesting… older data I guess would have been collected on film?
I’ve created an issue in our tracking system to implement a feature to ignore the CTF.

Ali

5