Strange output from Patch CTF

K3 camera, 0.27 pixel size, full frame motion, patch CTF. Could anyone comment on the weird plot (right side image with circle) ?
Thanks a lot

Hi @marino-j,

The weirdness here is CTF aliasing - at this pixel size and this defocus level, there is a resolution beyond which the CTF thon rings actually start oscillating between -1 and +1 faster than the Fourier-space sampling rate of the image. It is not a concern - the data is limited in it’s resolution well below the resolution where the aliasing starts.

Thank you for your answer !