Barndoors are devices that you can add to your lighting to help you to adjust how much light hits your subject and where that light is directed. There are many types of barndoors available; the one you choose depends on the lighting system that you use, as many are made to fit specific strobe heads. The most important thing to remember when purchasing a barndoor is to make sure to purchase one that is compatible with your lighting. For the purposes of this post, we will be discussing a small four leaf barndoor mounted on a 110 watt monolight strobe head, both available on our website.
To attach the barndoor to the strobe head, there are four screws around the center opening of the barndoor that need to be adjusted so that the strobe head fits between them. Then, slide the strobe head between the screws so that, when tightened, the screws will all sit about 1/2 an inch from the outside edge of the strobe head. You want to make them tight, so that the barndoor will not move when adjusted, but do not overtighten them (this may cause damage to your strobe head).
After your barndoor is attached, you can then adjust the leaves of the barndoor by pivoting them on the hinges. Bringing the leaves in, closer to the light, will narrow the beam of light that hits your subject. Be careful moving the leaves in too far, however, as this can cause the leaves to heat up and become extremely hot.
Determining where you want to position your leaves will take time and is something you will need to experiment with in order to get the style of lighting you want. Keep in mind that you will not necessarily get a straight edge from the barndoor leaves, as light between them does bounce around and will soften the harshness of the edges. To get a general idea of how the light will look in your photographs, turn on the modeling light on your strobe so that you can make basic adjustments to the leaves while examining the effects this has on your lighting.
Barndoors are a relatively inexpensive was to make your strobe more versatile. Take your time to setup one up and get familiar with it, and you can easily change the lighting effects from your strobe.