مصادر الضوء .. كتاب التصوير علم وفن

light sources

1- Natural: like the sun during the day, and the moon and stars at night.

2- Industrial:

(a) electrical:

Tungsten lamps.

electric arcs Gas discharge lamps.

. fluorescent lamps

Halogen quartz lamps

Flash valves (electronic flashlight).

(b) Non-electric:

Gas ignition

Kerosene lamps

Candles and matches.

Magnesium ignition.

Flash lights ignition.

How do you choose lighting equipment?

There are a lot of lighting devices. Which type suits you? This depends on the type of photos you want to make. We find that the beginner may only need an electronic flash device that he uses in indoor night photography. And when he comes forward, he may use it to open the shadows areas during daytime photography. But if your interest in photography is inside buildings and factories, you will need a number of photoflood light bulbs

Portrait photographer will need a number of photoflood lamps

Spotters and so on...

We will review together some lighting devices and what they are suitable for:

First: Devices that give continuous light: These devices have the following features:

<-1 The photographer can see the lighting effect and measure the brightness of the lighting using the reflected light exposure meter.

It can measure the degree of contrast in the light falling on the subject to be photographed, and thus or underexpose part of the subject.

He can make sure that the lighting distribution is set and that the background has sufficient lighting. He can also know where the shadows fall.

The disadvantages of these devices are:

1 – Not bright enough to stop motion in subjects

animated

It gives intense heat that the subject of photography can bear only for a short period of time (except for fluorescent lamps).

Among the types of devices that give continuous lighting:

Photoflood (Kelvin): This is suitable for general lighting and shadow lighting, and a light distributor can be added to it to distribute more light. It is used with A-type films in the case of color positive films.
photo flood

Blue photoflood devices (500 Kelvin): used as auxiliary lighting and to illuminate shadows in interior scenes when the original lighting is daylight coming from doors or windows. It is used with daylight films

Tungsten halogen devices (3200-3400 K): They give very strong lighting, and there are types of them with a battery, and so they can be used indoors and for outdoor scenes where there is no electrical source.

Spotlight devices: They are usually equipped with a quartz halogen bulb that gives a light temperature of 3200 (Kelvin): this gives a focused light with a high contrast that has specific and strong shades. Therefore, it is used with one of the previous types, especially with photofluid bulbs. They are excellent at giving
The main illumination of the subject, the light of poetry, or the illumination of special parts of the subject.

. Usually, the light beam can be adjusted to give a narrow or wide illumination, and a type B film is used with these devices for color positive films

Fluorescent tubes: These give light that is deficient in the red color and thus becomes unsuitable for color photography because it gives the subject in the image a green tinge. This green tinge can be fixed to a large extent with a special filter. And everyone must follow the manufacturer's instructions for these tubes