Hi, I have two datasets of the same sample. Both contain a similar amount of particles and both can be refined in RELION to 8.5A according to the gold standard. (Not yet separated into 3D subclasses) The first dataset has a pixel size of 1.891A/pix, as obtained from correlating to EMDB and PDB entries. However, the second dataset was acquired a few months later on the same instrument and has an apparent pixel size of 1.907A/pix (a 0.9% difference), when maximising the correlation to the first dataset (0.9991 in chimera). I am aware that magnification correction in RELION is not yet implemented. Is there a recommended way of combining/rescaling the datasets for RELION, while minimising resolution loss? I would be very grateful for suggestions! Best -- Matthias Brunner <[log in to unmask]> PhD student, Marlovits Lab -Research Institute of Molecular Pathology (IMP) -Inst of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA) Dr. Bohr-Gasse 3, A-1030 Vienna, Austria Phone: +43 1 79044 4791