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Lab 4: Aperature and Depth of Field



This lab introduced us to the concept of an aperture and of a depth of field. These two characteristics are commonly known as image focus — such as the focus of a camera.


Terms and Definitions

Objective lens: The lens that gathers light and focuses it onto the eyepiece. It dictates the function of the optical instrument.
Eyepiece: The lense that is closest to the user’s eye in an optical instrument (telescope, microscope, etc.)
Depth of Field: The distance between the shortest and largest distances by which an image can still be sharply seen. It is often described as the area in which an image is focused.
Aperture: The opening through which light passes through. It is responsible for the amount of light that can enter into a space.


Overview of Lab

By adjusting various combinations of lenses, light sources, images, apertures, and distances, you can create a real image. In order to find the relationship between the aperture and the depth of field, we changed the size of the aperture and observed the resulting depth of field. In order to find the depth of field, we moved both the image and object distance until a “clear” image could be seen.

The purpose of the lab was to investigate the relationship between the aperture and the depth of field.



Observations, Notes:

  • Smaller aperture corresponds with a greater depth of field.
  • See the graph below for more details

Analysis and Conclusion

We learned how the size of the aperture can increase or decrease the depth of field. This lab gave us a healthy understanding of how images are formed in a camera and the function of the aperture within that system. It was interesting seeing how the relatively complex physics that we learn in the classroom can be applied to such simple devices such as your camera.


Pictures and Diagrams