Theory Notes

Flashes:
A flash is an apparatus used in photography that directly produces a flash of artificial light at a color temperature of about 5500 K in order to help the illumination of the scene out. These flashes can be used for different reasons, for example to be able to capture a quickly moving object, or to create a different temperature light than the already given light of the area, however mostly, in order to illuminate the scenes that do not enough natural light to be able to properly expose the photograph. Most of the flash units found today are electronic, which have evolved from single-use flash-bulbs as well as flammable powders. In lower-end camera photography, flash units are usually built inside the camera. Whereas a higher-end camera allows for multiple flash units to be mounted through a standardized “accessory mount” bracket (often called a “hot shoe” (this is a mounting point on top of the camera in order to attach the flash unit)). Professional studio photography also uses a special way of flash light by using individual standalone units, which are connected to the camera through a flash synchronization cable, which will therefore allow the flash light to flash when the camera is shooting the picture. This will also allow having only one light-trigger to be attached to the camera, but it can inform other light-triggers and they would all flash. Nowadays, there are different kinds of flash units we can use. Often we use electronic xenon flash lamps. These contain a tube filled with xenon gas, in which electricity of high voltage is being discharged in order to generate an electrical arc which emits a short flash of light. Since 2003, most cameras that are targeted for consumer use have an electronic flash unit built in. Microflashes are also a time of flash unit; these are special, high-voltage flash units designed to give of a flash light with an exceptionally quick, sub-microsecond duration. These are mostly used by scientists and engineers when they want to capture a picture of a fast moving object during one of their experiments. There are also flashes especially for modeling, which do not go off at any given point, they maintain on during the entire photo shoot, which is helpful for the photographer because they are then able to know what the lighting is going to look like in each image. The use of the flashes: They are usually used indoors as the main light source when there is not enough natural light to satisfy the shutter speed. A fill flash illuminates a subject close to the camera while using an exposure long enough to capture some background detail. Another technique, is to point the light source up to, either to the ceiling, or to an umbrella which would reflect the light to the object, this is called bounce flashes (which is what we used for this project). This bouncing effect makes the image look more natural than if the light is directed directly to the object. These flashes do have problems. For example, built-in flash units often have a low intensity of the flash. Electronic flashes also have durations that are so short that the shutter speed needs to be used on focal plane shutter cameras. Finally, these flashes also create the red-eye effect. However over all, flashes are very helpful.