I'm new to this forum, and actually made up an account for one reason only. A question. I've noticed how some gyms, and other places as well has a type of lightning in a room where you look more fit/defined, both in body, and face structure. Would it be possible to produce/make a type of light which would have this effect, no matter the environment,or surroundings?
Light that is harder and at more of an acute angle will make a subject look more defined... such as a hard instrument (an open face instrument, or a fresnel, or other "hard" fixture) hung high and pointed down. That creates shadows, and shadows = definition.
Light that is softer and at a less acute angle, such as a soft instrument (big softbox, umbrella, hard light bounced into a reflector, etc.) and more at eye/body level and nearer the camera (more "straight on") will make a subject look "smoother" and less defined. Fewer shadows and softer more uniform light = less definition.
Fantastic Plastic Entertainment, Inc. fantasticplastic.com
Nicely put Todd.
To simply even further, with an example everyone can understand, think of the definition (and shadows created) by the one true light source -- the sun -- at noon on a cloudless day. It's very bright and far away (therefore very small). You can't get a much more harsh light.
Then add a thick cloud cover -- which diffuses that single hard source turning it into a much larger source spreading the light evenly, wrapping everything in a soft wash of shadowless light.