CTF estimation issue

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CTF estimation issue

Hi all,

I have problem with the CTF estimation job. The job runs fine but the output results seem not correct at all. I checked multiple micrographs the calculated defocus values were obviously wrong and there were no thon rings detected for some normal micrographs while very good thon rings for some really bad micrographs with a lot crystal ices. Nothing really special fot the input parameters, most were just default settings, and I tried multiple times for different datasets, all gave similar issues. Has anyone had similar problems? There is only one job that seems giving correct estimations, but for that dataset I actually accidently defined the particles as white (which shouldn't be) when I imported the movies. But this shouldn't really affect the CTF estimation, right?

Hi Alicia,

Hi Alicia,

This does not sound like normal behavior. Many datasets have been processed with cisTEM over the years and CTF estimation is usually pretty robust.

If you really want to work out what is going on, please pick a representative image and run ctffind manually on that image. If the image has decent signal and its power spectrum has Thon rings, but the fit doesn't work, please consider sharing that image and all the input parameters you used.

Without a specific reproducer, it is difficult to help.


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