Along with early film not being sensitive to light it also carried a very slow film speed. This was the main reason for the lack of sensitivity to light.
Film speed is measured in ASA numbers. The higher the ASA number, the faster the film’s speed and the lower amount of light needed to create a picture.
ASA speeds vary all the way from 10-2000 ASA. Early film used around a 10-50 ASA whereas modern films use around a 200-300 ASA which of course affects how much light is need. These are the following ASA speeds:
● 10-50 ASA – Early film, needs a lot of light.
● 100 ASA – Outdoor photography and indoors with flash.
● 200 ASA – Outdoor photography and bright indoors.
● 400 ASA – Outdoors and indoors, no flash needed.
● 2000 ASA – Highest speed possible with no light needed but results in a grainier resolution.
The major downfall with using a higher ASA in film creating is that the finished picture will have a much grainier resolution then a film using a lower ASA.
There are problems with both ASA extremes (i.e. 10 ASA & 2000 ASA) which means that a compromise must be made somewhere in between these two film speeds. The most commonly used and more appropriate film speed is therefore around 200-300 ASA; not enough light needed to burn a lot of electricity, blind everyone and make everyone hot but not a high enough film speed to result in a grainy resolution either.
Early TV was very similar to film in the way that excessive light was needed to create a picture (Baird studios 1929-1936).
Even with scenes filmed outside, excessive lighting was always needed.
As film and years progressed later electronic systems needed less extreme lighting but still used a considerable amount of lighting. Film and equipment has changed throughout the ages and higher film speeds have since been created to make film making more practical.
Modern domestic video cameras along with professional equipment are very sensitive to lighting yet lighting is still used. The following information will provide an explanation as to why we still insist on using lighting.
Movie lighting produces depth, shape and texture in a medium which is essentially flat and two dimensional. It also can indicate to the audience which time of day it is or what season it is.
There are a few other major purposes of lighting, one of these being its ability to create a sense of realism. For example a particular scene could be filmed with the lighting coming from the side of the window, which in affect would seem like the sun shining through the the viewer. Other major benefits to lighting are that it works well in emphasizing colour and reflection. Atmosphere and mood is another thing affected by lighting in a film; for example a Tim Burton movie will use very dark lighting to create an eerie, gothic, burtonesque feel.
Many different lighting techniques are used in film to create these effects. The main basic lighting setup is four point lighting. Four point lighting consists of four primary movie lights; key light, fill light, back light and background light.
The purposes of each light are as follows:
● Key light – The subject’s main light source in the scene.
● Fill light – The light used to reduce subject shadows and contract.
● Black light – a light placed behind the subject that illuminates the back and hair, separating the subject from the background and adding additional highlights to the scene.
● Background light – a light that illuminates the background or set and, depending on it’s brightness, establishes a low – or high key mood.
These are some basics on lighting a scene:
If the scene has two actors, set up individual key lights for each.
Try to come from an angle consistent with practical lights in the location such as lamps or windows.
The fill will control how much contrast the scene will have.
On some occasions a fill light might not be needed.
To separate actors from backgrounds and add depth, introduce backlights.
