Aperture & Depth of Field - Cinematography

This past week I have been learning about aperture, what it is, what it affects and then physically applying it to photos, comparing each different aperture setting. So, first of all what is aperture?

Aperture and Depth of Field example

Aperture controls how open the lens is which in turn lets a certain amount of light come in through the lens. Aperture is measured on a camera by f-stops. If the f-stop is high then the opening of the lens is small but if the f-stop is low then the lens is opened wider and when the lens is opened right up, more light can get in. Aperture is used in conjunction with shutter speed to gain the correct exposure and as the aperture changes, the shutter speed needs adjusted to gain the correct exposure.

Examples of different f-stops

The aperture affects the depth of field of your shot. The depth of field is the range of acceptable sharpness in your image. The depth of field can either be shallow or deep and defines whether your background is sharp and detailed (deep) or whether your background is blurred and shallow. Bokeh is a japanese word that is used to describe extreme background blur (out of focus). If you have a higher f-stop (small lens opening) then your depth of field will be deeper and if the f-stop is lower (wider aperture) then the depth of field will be shallower. Above are two examples of the same image but using different f-stops.

Here is a YouTube link that discusses aperture, f-stops and shows a progression of images showing different depths of field:  https://www.youtube.com/watch?v=ZhDODaUN3pI

I am slowly getting my head around aperture, depth of field and shutter speed and how they all relate to one another. Check out this blog next week for the next update of things I have learned to do with cinematography.