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Because I am not very good at explaining photography, I make a translation of an article that explains DoF clearly and clearly. The purpose is only to give the best answer as i can.
Understanding DEPTH OF FIELD or DoF in photography is a field or zone in a photo that has sharpness (clear). This field may be in front of, parallel to or behind the subject of a photo.
The subject of the photo is the statue, but note that the area around the statue, such as the grass, the statue holder and a number of other things are clearly visible. Compare with the background of the statue that looks blurry (unclear).
Well, this sharp area is known as DEPTH OF FIELD or DoF in photography.
Two Terms Regarding Depth Of Field
In photography there are two terms related to DoF, namely:
Shallow Depth of Field
Shallow = Shallow.
This term refers to the "narrow" Dof. It means that the field is sharp and clearly not much. Usually many are used for portrait photos using the bokeh technique.
Deep Depth of Field
Deep = Deep
The second term is the opposite, namely Deep Depth of Field aka DoF In. Fields that are sharp and clear are very broad and even thorough in a photo. Usually used in landscape photography.
What Affects Depth Of Field a Photo?
There are three things that will affect the DoF in a photo, namely:
- Focal Length
a) The smaller the aperture value (can be seen from the number behind the letter "f", it means that the DoF gets smaller, narrower.
f / 2.8 means having a Dof that is narrower than f / 5.6
f / 11 means having a wider Dof than f / 5.6
The longer the focal length of the lens, the smaller the Dof.
On telezoom lenses, such as 18-55 mm (DSLR camera kit lens) with f / 3.6-5.6, the widest DoF f / 5.6 can be obtained when the lens is the same in the shortest position, which is 18 mm, otherwise the narrowest dof is obtained when the lens is extended at 55 mm (f / 3.6).
Distance between the camera and the subject
The closer the camera is to the object, the narrower the DoF is produced. Conversely, the more distant the subject is with the camera, the wider the DoF is produced.
For example, using an 18-55 mm lens, when you shoot from a distance of 1 M from the subject at a focal length of 18 mm, it will look a lot of parts that are blurry and unclear. Try backing out (without changing the settings), it will show that the sharp space will increase. Even without changing the camera settings.
This happens similar to if you lengthen or shorten your telezoom lens. Remember the telezoom lens is actually made so that the photographer doesn't need to go forward and back a lot, so the function is the same.
Why is Knowing the Depth of Field Important?
Try shooting a landscape with a lens setting or using a lens that produces a shallow or narrow depth of field, like 50 mm f / 1.8 which is usually used to produce bokeh.
The result will be very unsightly. There will be a lot of blur. Even though landscape photos or shooting landscapes will be better seen when as clear and sharp parts as possible.
Conversely, making blurry or blurry parts in portrait photos or macros, will throw away the "insignificant" or "unrelated" part of the photo subject and add artistic value to a photo.
By knowing what DEPTH OF FIELD (Dof) is in photography, this will make us know when and what technique to use and what camera settings to produce good photos.
The term Depth Of Field, or DOF in photography and film relates to the field of focus of a lens or any type of optical imaging system.
Actually, a lens can only focus precisely on on specific plane at a time, the plane of focus, or POF. On each side of the POF, the sharpness decreases gradual. How gradual the sharpness decreases, depends on the lens type, the aperture size, and the size of the format (the film, or the sensor).
Now, the DOF, or the Depth Of Field, is the distance from the plane of focus, in which objects in the image still appear acceptably sharp to the human eye and under normal viewing conditions.
Or to put it short: Depth of field is the area in which objects appear sharp in an image.
Depending on the type of image you want to create, you may want to have the entire image sharp, for instance for landscape photography, which would mean a large DOF. This will require you to use a small aperture (large f-number). At other times you may wat to emphasize the subject, and put less emphasize on the foreground and background, you want to set your subject apart. This is often used for portrait and macro photography, and requires a large aperture (small f-number).
While in photography, the terms large DOF or small DOF are used, in film and cinematography, the terms deep focus and shallow focus are more commonly used.