1 sphere = 12.56637061 sr; A sphere is a three-dimensional geometric shape that is perfectly round and symmetrical, with all points equidistant from the center. It is a unit of measurement in solid angle

1 st = 1 sr; The "st" (steradian) is the SI unit of solid angle, representing the extent of a cone's surface that intersects a sphere at its center. It measures spatial coverage in 3D space.

1 sr = 1.0 sr (Base Unit); The steradian (sr) is the SI unit for measuring solid angles.