appear to "wrap" the light more, but in terms of actual cause and effect the "wrap" effect results from the light bouncing off ceiling and walls back into the shadows created by the key light from many different directions. An advantage of a dedicated studio space vs. location shooting is that the "spill fill" becomes a predictable variable in the overall lighting strategies. Some studio photographers aim their dedicated fill source at a white wall behind the camera near the ceiling to intentionally create omnidirectional "wrap around" fill similar to natural skylight and eliminate the reflection "catchlight" a direct fill source will create in the eyes. With location shooting the spill fill variable will cause the same lighting strategy to produce different result. Outdoors there is no spill fill created by artificial sources which is why cap style speedlight modifiers perform differently outdoors and large indoor spaces which reflect very little spill fill. Skylight outdoors is "spill fill" in the sense it reflects the light of the sun in a way the photographer can't control unless a reflector or flash is used to modify the three f/stop difference in brightness that typically occurs between direct sun and shade. Cause and effect A systematic approach for visualizing the cause and effect is to start from a baseline set-up with the testing done outdoors at night or in a large darkened indoor space where there will be no reflected "spill fill". Set a camera on a tripod at the aperture desired for depth-of-field and start with just the fill source located centered and chin level to a subject facing the wearing black and white textured clothing. Raise fill power until detail is seen in the black clothing. The nose on front of the face will be observed to be lighter than the ears due to the inverse-square fall off of the fill source and it will create a light-to-dark gradient. The contrast of the gradient can be altered by changing the distance of the fill light from the subject. With most recording media (B&W negative being the exception) the white clothing will not be correctly exposed when the fill light is adjusted based on shadow detail. That problem is solved by adding the key light which for this exercise should be placed 45° above the eye line and 45° to the side of the nose of the subject facing squared to the