Create panel > Lights > Photometric Lights > Click Target Point or Free Point. > Intensity/Color/Distribution rollout > Choose Isotropic in Distribution list. > Click in viewport to create light.
An Isotropic light distributes the light equally in all directions.
To create a light with an Isotropic distribution:
Choose Photometric from the drop-down list. (The default is Standard.)
In the Intensity/Color/Distribution rollout, select Isotropic from the Distribution list.
You can use the Move transform to adjust the light.
You can also use the Place Highlight command to change a light's position.