Well, there are two controls for light:
Size, relative to the subject, and
Distance from the subject.
Distance from the subject affects the gradation across the field,
so if you want an even light across the field, you move the light back,
but if you want a variation across the field, the light belongs close to the subject.
I suppose if one is making a clinical image,
the light should be further away,
but for an expressive image, you can bring it close.