[3dem] Strange CTF fit

[Basil Greber]

Hi Andrea,

The Thon ring fitting failed altogether for this image. It looks like the image is closer to focus than the fitted CTF would indicate. Have you tried lowering (substantially) the minimum defocus value that CTFFIND4 is considering in its search?

Best regards,

Basil




> Am 10.10.2022 um 18:29 schrieb Andrea Dallapè <andrea.dallape at unitn.it>:
> 
> Dear all,
> 
> I would like to ask for your help and expertise.
> I have a dataset CTF-estimated (with CTFFIND4). A subset of these micrographs have a strange CTF fit of 716.80 A (all of them have the same value).
> The micrographs seem to be fine, and the FT and Thon rings are good as well (see attached image below).
> 
> Do you know why this happened? And do you have any suggestions on how to proceed? Should I discard this subset of micrographs or can I use them?
> 
> Thank you for your kind help and attention.
> Best,
> Andrea
> 
> <Screen Shot 2022-10-10 at 19.24.04.png>
> 
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