Resolution Loss in Helical Refinement with Unbinned Data

Hello everyone,

I’m working on a helical reconstruction in CryoSPARC and struggling to achieve the best possible resolution. I’m seeing a significant drop in resolution when I use unbinned data in the Helical Refinement job.

Here’s what I’ve observed:

With a box size of 960 pixels and binning by 3 (resulting in a 320 Å box), I can get a resolution of about 8 Å.
Unbinned Data: When I try using unbinned data (960 Å box) or binning by 2 (480 Å box), the resolution worsens to above 10 Å. I also see a sharp drop in the FSC plot.

I started with the 320 Å binned data and proceeded through 2D classification, ab-initio, and 3D classification. Then, I re-extracted the particles without binning, but the result was not as good as the binned one!

Any insights or suggestions would be greatly appreciated!