الأرقام الإرشادية .. كتاب فن التصوير الفوتوغرافي

Indicative numbers:

There is no doubt that the power of illumination reaching the subject depends primarily on the subject

Close to the light source

If you turn on the flash very close to the subject - for example, one meter - then the

The lighting will be more intense than if you lit the flash at a distance of three meters.

The difference will be clear between the two cases on the shots, and in order to ensure a good exposure for the shots, the flash designers deliberately find indicative numbers that are usually engraved on the back of the flash and vary according to the speed of the film used. M aforementioned. In order to find the appropriate lens aperture, you must divide the distance between the flash and the subject by the guide number according to the following example: Suppose that the speed of the film you are using corresponds to the guide number 80, and when you measure the distance between you and the subject using the focus ring, it turns out that you are 3 meters away from it, and divide 80 by 10, the answer will be It is 8, which is the aperture number of the lens to be used.

On the contrary, if the depth of field is of great importance in the shot, then the priority in this case is given to the lens aperture. If you're shooting a portrait, it's a good idea to throw the background out of focus in order to focus attention on the portrait itself. In this case, you should choose a large lens aperture, such as f4. Section 4 on - the indicative number - and the answer is 20 feet, meaning that you must stand at a distance of 20 feet or the equivalent of 6 meters from the subject when photographing it.

The camera lens may not be able to form a good portrait shot at a distance of 6 meters, and here you have to separate the camera from the flash and bring it closer alone, while keeping the flash in place and connected to the camera with a special wire for that.

In general, the rapid progress of flashes canceled this method, which requires some calculations, and replaced it with another, simpler method, whereby the indicative numbers were replaced by an exposure table on which different film speeds, different distances, and lens apertures suitable for these distances were written - see the attached table.

Flash Flash Flash: There are four basic techniques that cover all situations in which it has to be used

Flash is very important.

1- Direct flash.

2- The bounce flash.

3- Flash with the sun

4- Painting with light

1- Direct flash: directing the flash directly towards the subject, as it is the main light source. In this way, we can use the flash while it is installed on the camera or in a place far from it. It is worth noting that using the flash that is installed on the camera is not the best way, because the lighting at that time is not attractive and without shading shadows and habit! Often the only shadow formed is a black line behind the subject if the subject is standing behind a nearby wall.

And for portrait photography, in particular, the flash must be positioned higher than and to the side of the camera in a way that illuminates the face at an angle of 45 degrees in the same way as

We talked about it in Chapter Four.

2 - Bounce Flash: Although the direct flash gives clear illumination to the subject, this is at the expense of extreme contrast, as the shadows come heavy and black behind it, and the highlights are very contrasting.

Here comes the role of the rebound flash, which nullifies these matters. The light bouncing from a flat surface to the subject gives soft illumination. Light shadows, especially for portraits with people.

Bounce flash photography is not difficult, instead of aiming the flash directly at the subject. You should direct it to a nearby flat surface such as a ceiling or a wall. Calculate the distance between the flash and the bounce surface, then the distance between the bounce surface and the subject. Divide the sum by the guide number and you get your desired aperture You need to expand your aperture additionally sometimes. When the light falls on the surface of the bounce, a quantity of it is absorbed and the rest is bounced back to the subject. The amount of light absorbed varies according to the color of the wall. Dark colors absorb more light than they reflect, while light colors reflect most of the incoming light. Therefore, you must take this aspect into consideration when deciding which aperture lens to use

This method is that a simple increase over the pause that you get from the results of the previous calculation is sufficient. The ceiling or middle wall of the color sink needs to be increased by two additional stops. While the darker surface needs three you will find with

Other pauses, at least, be careful when using colored reflectors with color film, as a tint of color will appear in the color of the reflector on all images taken with its help. So you have to choose a surface

White with color film. Try the backlighting method before you use it seriously. Experience is enough to make you proficient in this field.

From 3- Flash with the sun: It is a method to control the degree of light contrast when photographing outdoors. By dictating blunt shadows with flash light. This method is very easy, after you measure the exposure and adopt a suitable aperture and speed - make sure that the shutter stop is synchronized with the used flash - divide the guide number by the aperture number and the answer is the distance at which the flash should be placed in relation to the subject.

As for the flashes that do not contain indicative numbers, you must resort to the intuition method to find out the necessary distance

Remember that using the flash with daylight reduces its light intensity by 7 half, so you have to try it with outdoor photography to see the distance at which the flash lighting is effective.

The advantage of flashing with the sun is that you can move your subject freely from the sun because you will ensure that the harsh shadows are filled with A light

4- Painting with light: Go back to the pictures you took at night, and you will find that some details would have been clearer if you had used some light to show them. This is what the flash offers you. During a long exposure to a subject, you can use the flash manually to illuminate certain parts of the subject. Point, no doubt, to the parts you want to show clearly, then turn it on manually while the camera is installed on a three-legged bracket and its shutter is opened by the capture wire. This method is also known

The last thing produced by flash designers is a small reflector that can be installed on top of the flash and can be moved up and down on demand to facilitate the illumination method for the photographer. The translator .

With Open Flash, its beauty lies in the fact that you can use the flash more than once and for more than one part of the same image. But beware of your appearance in the shot. Many of the wonderful shots were spoiled because of the appearance of the photographer holding his flash in the center of the picture to illuminate some parts of it.