size matters {80/365}

Oh, yes indeedy, friends.  Size does, indeed, matter. Well, as far as light sources goes. . . . .

General rule of thumb, the smaller your light source the harsher the light, shadow, and spectral highlights (reflection of the light source).

Below are a few examples.  Little setup, here.  I have a strobe on camera right in the closed loop/rembrandt position and that's going to be fitted with three different light modifiers.  I am positioned 5' from the white background and the strobe is positioned 3' from my face.

Exhibit A:  Small Light Source

Light modifier is a 5" reflector.  Notice the harsh shadows under my nose and on my neck. The sharper the transition between light and shadow, the smaller your light. Also, take note of the background for future reference.  It's a dark/medium gray.  Overall color is pretty saturated.

Exhibit B: Medium Light Source

The medium light source is a beauty dish about a foot and half diameter. The shadows are slightly softer - there's a slightly longer transition between dark and light. Plus, the background is appearing lighter!  HMMMMMMmmmm.  It's now a 13% gray!  Color isn't quiiiiite as saturated.

Exhibit C: Large Light Source

Now the light is coming from a 60" softbox. MUCH, softer! The starkness between light and shadow is much smoother and the background is almost more evenly lit compared to my face!  Color is more evenly toned.

There you have it!  If you control the size of your light source you control the softness/harshness of the outcome.  You also dictate the spread of your light on your subject and background AND how saturated your colors are.

All shots:  Canon 50mm 1.8mm - f8 @125th 100iso; shot 1: 5" reflector; shot 2: 32" beauty dish; shot 3: 60" soft box