Default box size for ab-initio jobs

Hi cryosparc experts,
I did the motion correction, CTF estimation, auto picking, and particle extraction in relion 3.0, the box size I set is 256 pix. After the particle extraction, I tried to import file to cryosparc, the importing and 2D classification jobs worked well. However, when I carried out Ab initial reconstruction, the output mrc file showed the box size is 128 pix, I don’t know why. Does anyone know what happened to the box size? And how to keep it the same 256?
Yours sincerely,

Hi Lingting,

128px is the default box size used for ab initio reconstruction (at the default start/final resolution values). This is for speed, to reduce computational cost - there is no need to run in a box size of 256 if you are using a maximum resolution of 12 Å, and the resulting volume will be automatically resampled in subsequent refinement jobs.


Hi Oli,

Thanks for your reply. I got it.