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Assessment of data quality

3 posts / 0 new

Tue, 03/26/2019 - 22:25

rddey80

Dear Members,

I see wavy background around all the 2D class averages. Can someone explain what could be the reason for this? Is it something related with energy filtering during image collection or something with data processing? Please see the attached image.

Thanks for your time.

Raj

File:

Screenshot from 2019-03-26 21-15-29.png

Tue, 03/26/2019 - 23:14

timgrant

Hi Raj,

It looks a little strange, like something has gone wrong in the CTF estimation - what sort of defocus were these images taken at? Are they all very similar?

Tim

Wed, 03/27/2019 - 09:13

(Reply to #2) #3

rddey80

Hi Tim,

This is a phase plate data. I found the defocus range is 4000A to 46000A when sorted by Defocus after Find CTF. Is it possible that I included some images with high phase shift? I noticed that beyond 70 degree phase shift, CTF fit result does not look good. But, that is about 8% of the entire data set that has phase shift beyond 70 degree. Any suggestion to improve CTF estimation?

Thanks.

Raj

Source URL:https://cistem.org/assessment-data-quality?page=0