In simple terms, Depth Of Field is the choice you can make, as the photographer, as to how much of your chosen frame you want in or out of focus depending on what you wish the viewer's attention to be drawn to.
Aperture is the main contributing factor to controlling the depth of field as it is the one that can be changed without having to alter the composition of the picture. The smaller the aperture the larger the f number and in turn the greater the percentage of the image looking sharp as it's a more concentrated beam of light and then at the other end of the scale, the smaller the f number the larger the aperture which means more of the image will appear out of focus as the light is allowed to rush in willy nilly.
Other factors that can affect the depth of field are the distance between you and the subject of focus with the closer you being to your subject then the shallower the depth of field as well the distance from the subject to the background also having an affect as the further away the background the more blurred the background will be.
Focal length can also be used to change the depth of field with a longer focal length producing a shallow depth of field and the opposite being true for short focal lengths.
Sensor size is something else that can affect the depth of field which is why pocket cameras that possess a small sensor often produce images where everything is in focus whereas a full frame or cropped sensor of a dslr is much larger and allows you to produce a shallower depth of field.
Circles of confusion are just that, confusing circles that form on the limits of depth of field but for the purpose of this blog and my sanity, I wont go any further into detail and instead recommend you revert back to the passage onaperture and study how the detail changes in the images below that were all shot at the same focal length but at different f stops with the exposure being adjusted according to help maintain the right light balance.
Aperture is the main contributing factor to controlling the depth of field as it is the one that can be changed without having to alter the composition of the picture. The smaller the aperture the larger the f number and in turn the greater the percentage of the image looking sharp as it's a more concentrated beam of light and then at the other end of the scale, the smaller the f number the larger the aperture which means more of the image will appear out of focus as the light is allowed to rush in willy nilly.
Other factors that can affect the depth of field are the distance between you and the subject of focus with the closer you being to your subject then the shallower the depth of field as well the distance from the subject to the background also having an affect as the further away the background the more blurred the background will be.
Focal length can also be used to change the depth of field with a longer focal length producing a shallow depth of field and the opposite being true for short focal lengths.
Sensor size is something else that can affect the depth of field which is why pocket cameras that possess a small sensor often produce images where everything is in focus whereas a full frame or cropped sensor of a dslr is much larger and allows you to produce a shallower depth of field.
Circles of confusion are just that, confusing circles that form on the limits of depth of field but for the purpose of this blog and my sanity, I wont go any further into detail and instead recommend you revert back to the passage onaperture and study how the detail changes in the images below that were all shot at the same focal length but at different f stops with the exposure being adjusted according to help maintain the right light balance.
