Spike in noise model

Troubleshooting
1

Hi all,

I’ve processed a data set collected on DE-64 (8k x 8k). And I noticed that there is a spike in the noise mode plot at 8.08Å.

de64.jpg874×564 66.7 KB

The pixel size for the micrograph is 1.01Å/pixel. What could cause this spike? And will it affect the refinement? Thanks! Please let me know if you need additional information from me.

Thanks,
Wei

2

Hi @wxh180, sorry this post got lost over the months! Have you had any insight into explaining this feature?
It may be related to postprocessing (gain correction) that the camera does, but it’s unclear whether it would matter for reconstructions that go beyond 8A.

3

Hi @apunjani , No problem. Thanks for following up on this. It was something to do with the arrangement of the panels on DE64, which results in large spikes in FFT. Ben wrote a script to filter these pattern noises and the spikes were gone after that. After fixing this problem, the refinement was able to go beyond 4 Å.