Aperture & Depth of Field

Yesterday we talked about aperture and its relation to depth of field. A small aperture will provide a large depth of field (everything in focus). A large aperture will provide a small depth of field (only certain parts in focus). 


However, there remained the question: Why does a small aperture provide a large depth of field and a large aperture provide a small depth of field? So here is the answer.


When you increase the aperture you are increasing magnification. When you magnify an image, only parts of it remain in focus. So, decreasing the aperture has the opposite effect. It lessens the magnification and allows more of the image to remain in focus.


How does a camera do this?


Here is a long but good article on how a camera works.


Hope this clarifies things a bit. Until next time!