عمق المجال Depth of field .. كتاب فن التصوير الفوتوغرافي

Depth of field

Now that you know the relationship between aperture and shutter speed, let's move on to their effect on focus. There is no doubt that you now think that focusing is turning the focus ring in the lens until the image becomes clear in the viewfinder only. But this is really the simplest result of concentration.

An important fact that will directly affect the outcome of your shots in the future is how much of the subject you want visible in the shot.

Do you want the whole subject to be sharp in prominence, with clear details, or do you want the most important part of it to be sharp in prominence and throw the rest out of focus? This is what you can determine with the help of depth of field.

Wide means the sharply protruding area of ​​the shot is called depth of field. The depth of field varies from one shot to another, so you, the photographer, can control it and adjust it according to your desires, by using the aperture of the lens, either by widening it or narrowing it. Apertures mean that your depth of field will come out shallow and focused only on a specific area. Narrow apertures mean that your depth of field will be sharp throughout the shot. You can pre-determine the distance at which your sharp bits will appear in the following way: Most cameras that have a focus adjustment ring have a depth dial. area . It is usually located directly behind the focus adjustment ring (hold your camera and make sure of its location, you will find it among the numbers of the focus adjustment ring. Aperture numbers. The depth of field scale has numbers similar to the lens aperture numbers, but the difference between them is that these numbers are repeated on both sides of the scale, starting with the largest aperture centered and finished with the smallest aperture on either side.Now choose an aperture,say F16,focus on a subject close to you,then look at the distance recorded on the focus adjustment ring,it could be 15 feet-depending on how far you are

The topic is about you - this is the distance within which your subject is in focus. Read now. The two distances whose location matches the F-16 location on both sides of the depth-of-field scale. You will see that the F-16 corresponds to 10 feet on the first end of the focus adjustment ring and 25 feet on the other end. The result is that you will know in advance that any distance between 10 feet and 25 feet will be in focus for your subject.

If you do not fully understand this idea, do not worry, we will learn a lot about depth of field in a broader way in the subsequent chapters, but for now let us review together the following facts:

1- When you take a picture of a face and you want to emphasize the face without the background, the simplest way to do that is by throwing everything except the face out of focus using a wide aperture lens. Not to lose the main point of interest in your topic in a sea of ​​unwanted details.

2- There is a scientific fact that says that the closer you are to your subject, the shorter the depth of field. This fact is to achieve better pictures. Take advantage of

3 - You will sometimes find that the depth of field provided by the focus adjustment ring is not sufficient to achieve the desired, and that you need additional depth of field to achieve more clarity of the scene. Here you have to do the following:

Set the focus adjustment ring to infinity, and you will find that the infinity signal 00 corresponds to the bisector of the signals in the depth-of-field scale because the infinity signal is the last signal in the focus ring, so you will have only half of the depth-of-field scale to use.

Now suppose you are using an aperture of say f8, you will find that only one of the f8 numbers on either side of the depth-of-field scale will be used only because the number

It is the other (right) There is nothing corresponding to it in the focus adjustment ring, but the amazing thing here is that if you rotate the focus adjustment ring to an infinity position opposite the right F-8, your subject will remain sharp in prominence, and in addition to that, if the maximum distance that appears sharp in prominence foot you will now gain another 15 feet this way.

And you will be able to get an additional depth of field that provides you with clarity

more for the scene.

These were some of the basic information you must know about depth of field to become a good photographer. One thing remains, the more you practice making the most of depth of field, the more you'll be able to improve the quality of your output, because oftentimes it's the main factor in making or breaking an image.