The depth of field is the area in the shot where all the items in it look sharp. You can say the depth of field “decides” what is going to be sharp in the picture and what is not and by that creating depth in the picture.
There are two types of Depth in the image:
Shallow Depth is a field in the shot where the focus area is tiny. We usually use it to direct the viewer’s attention to something specific in the frame. You might also see it a lot in interviews. The DSLR cameras became very famous because of their ability to create a shallow depth of field very quickly. Anyway, what you need to remember is that the closer you are to the photographed object, the shallower the Depth of field is going to be.
Deep Depth means that the entire frame from background to the foreground is as sharp as possible.
Aperture – This mechanism is in charge of the size of the lens opening that determines the amount of light entering the lens and also the angle of light rays that are hitting it. Aperture is measured in f/stops, for example, f/2 or f/16. F/2, For example, represents an aperture diameter that is 1/2 the focal length of the lens. Therefore, f/2 will be bigger than f/16.
A larger opening will decree the Depth of field. If your camera has an internal neutral density (ND) filter, you can dial this in.
Focal length – The longer the focal length of your lens is, the shallower the Depth of field will be. In other words, the more you magnified your object, the less Depth of field you’ll have.
The 3rd factor is the distance of the object from the camera– The closer you are to the filmed object, the shallower the depth of focus will be, the farther the object is- the higher the Depth will be.
Many tables can help you do the calculations needed, but there are not always accurate and sometimes missing the new cameras and lenses out there. I recommend playing with those 3 factors until you’ll have complete control and understanding of them. If you don’t have time for playing, many apps can help you to calculate the Depth of field. Some of them not only does excellent calculations with a depth of field, but it also calculates exposure, running times, and more.
Shooting with Depth of field needs to be considered while planning the shooting breakdown. Let’s say you are shooting a scene with a long shot, a medium shot, and a close-up; you may need to increase the light in the medium shot to get the Depth of field you want, even to change the lens. So you need to know about it before you shoot the scene.
The Depth of field is a great way to make a good picture, but also good to manipulate the viewer’s emotions and concentration. Don’t use it just for the sake of using it. On the set, while looking at the picture on the monitor, you should always ask yourself, is it what I want? How does it serve the scene’s theme and the premise of the film? Using this tool right will make your movie look more professional and exciting.