Umbrellas soften, broaden, and diminish the light output of any tungsten or flash light source. Umbrellas with a white interior will soften and weaken light more than an umbrella with a silver lining. A white umbrella without a black backing may also be used as a makeshift softbox, although the use of the light will not be as efficient as with a lightbox.
Choosing umbrella size is determined by the size of the subject, and the strength of the light supply being used. Choosing an umbrella surface is as subjecetive as choosing a paint and brush.
Unique blue reflective surface converts a tungsten light source (3200°K) to Daylight (5000°K) temperature.
Color correct a tungsten light source for use outdoors.
Equivalent to mounting an 80A filter onto a lens, or a full CTB filter onto the light source.