[3dem] Relion and De-20 Camera system

[Reza Khayat]

Hi,

We're processing data collected on a Direct Electron DE-20 Camera System. CTF correction of particles during a Relion refinement run over-emphasizes the high frequency terms such that we get pincushions as 2D class averages. Turning off CTF correction or only phase flipping fixes this problem. Does anyone have a trick for doing amplitude correction with DE-20 data?  Should I play around with the _rlnAmplitudeContrast value in the star file? Thanks.

Best wishes,
Reza

Reza Khayat, PhD
Assistant Professor
City College of New York
Department of Chemistry
New York, NY 10031

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