Shoot Through Umbrellas
Shoot through umbrellas, also called white, soft, or translucent umbrellas, are one of the most common umbrellas used by photographers. When you need to diffuse your light source, shoot through umbrellas are a good choice. The material used will produce results similar to a softbox, diffusing your lighting source and softening the light that hits your subject.
When you use a shoot through umbrella, position it between the light and your subject, adjusting the position of the light in regards to the umbrella until you get your desired effect.
Reflective umbrellas are also useful modifiers, allowing you to bounce light directly onto your subject without the use of standard reflectors. This keeps your studio more organized and clean and still allows you to get the benefits of a reflective surface. Reflective umbrellas come in many different colors; black, silver, gold, and white are a few of the options available.
Gold: Use gold reflectors to warm up your pictures.
Silver: Silver reflectors can be used to brighten your picture, without affecting the color of the light.
White: Use white reflectors to bounce light into shadows, without affecting the quanity, quality, or color of light being cast on your subject.
Black: Black reflectors act in a subtractive manner, removing excess light from your photos.
You will also notice that some umbrellas have black backing and some have white. An advantage of the black backing is that it will keep out more unwanted light and heighten the effect of your reflected light.
When you use a reflective umbrella, position the light source between the umbrella and the subject, with the opening of the umbrella pointed towards the subject.
In both cases, the size of your umbrella will impact your end results. Just remember that the larger the umbrella, the more your light will be spread out. Using smaller umbrellas can give you more focus, while larger umbrellas can illuminate more area. This is something you'll have to play with to know what you like best; most photographers learn with a 33" umbrella because they are an inexpensive way to become familiar with how they work.