[PyMOL] sphere_scale help

[Gregory R. <rs...@co...>]

Hi,

I'm a fairly new user to PyMol and am having some trouble with the 
sphere_scale command. I understand that if I want to draw a sphere 
around the x'th ca atom, I can use:

/show spheres, ////X/ca/

However, what if I want that sphere to have a radius of 3 angstroms, or 
6 angstroms, etc.

  I understand I can use set sphere_scale, 1, ///X/ca but what is the 
default scale of 1? Is it 1A, is it something else?

Thank you for your help!

Kind regards,
Greg