Resolution estimation worsens after unbinning particles

I have a pair of datasets where most of the processing is done with Bin2 particles (Fourier cropped to 1/2 box size during extraction). Non-uniform and local refinements for a cleaned up set of particles give 3.9 and 4.3A respectively. Upon re-extracting the particles from the NU job at full pixel size, the two refinements drop to 4.1 and 4.7A respectively. Similar trend is observed with the 2nd data set. I’m trying to understand the reason behind the decrease, as I would have expected at least the same estimated resolutions. Nyquist for binned particles would be ~3.4A. Any thoughts on this behavior are much appreciated.

Hi @andreym, this is unexpected - theoretically as you pointed out, resolutions shuold at least stay the same with unbinned particles extracted at the exact same coordinates.
The extraction box size is the same in both cases, and only the bin size is set differently, correct?

Can you provide any other information:

  • how many particles total and how many micrographs
  • post the FSC curves before and after
  • size of the particle, any symmetry?