Hi Jon, You can set the ChimeraX scalebar to whatever length you want using the graphical user interface menu Tools / Depiction / Scale bar, or the command (e.g. "scalebar 10000" for 1 micron). It is important to check that the pixel size on your tomogram is set correctly (in Angstroms). If it is not, for instance if the tomogram file just used a default value like 1, then the tomogram won't be scaled to the right size so the scalebar will not be correct. Use ChimeraX menu Tools / Volume Data / Map Coordinates to show the "voxel size" setting of the tomogram. You can use that panel to change the voxel size if it is not set correctly, and then save a new copy of your tomogram as a .mrc file with the correct scale. Tom
On Mar 11, 2026, at 1:09 PM, Choy, Jon via ChimeraX-users <chimerax-users@cgl.ucsf.edu> wrote:
To whom it may concern:
I hope this email finds you well! I am currently working with tomograms and had a question about scale bars and how they are determined. I've looked through the chimearx help dialog and it seems that the scale bar is default set to 100 angstroms, is this true?
Does chimerax somehow know to pull from the metadata of the tomogram to determine the scale size? In my case I am working with segmented mrc files and am using the volume setting in the volume viewer to display the rudimentary 3D model. However, I am not sure how to verify that the 100 angstrom scale bar is correct?
Any assistance would be greatly appreciated!
Best, Jon _______________________________________________ ChimeraX-users mailing list -- chimerax-users@cgl.ucsf.edu To unsubscribe send an email to chimerax-users-leave@cgl.ucsf.edu Archives: https://mail.cgl.ucsf.edu/mailman/archives/list/chimerax-users@cgl.ucsf.edu/
