Hi everyone! My name’s Perri. I’m an undergraduate student at University of Miami’s Rosenstiel School of Marine and Atmospheric Science. I’m currently majoring in Marine Biology; however, one of my aspirations is to incorporate photojournalism into my career. As such, I’m taking introductory classes to photojournalism and digital production.  Every week or so, my photojournalism class assigns me different tasks to learn about the basics of photography - like depth of field, motion, lights and shadows and portraiture (just to name a few).

I thought it would be cool to share what I learn with others who are just starting out in photography. So, for the rest of the semester, Ill be chronicling all of my adventures (and misadventures!) in learning basic photography.

Lesson #1: Depth of Field

My first assignment in class was about how to accomplish varying degrees of depth of field. Depth of field is defined as the distance between the closest and farthest objects in an image that is in acceptable focus. But remember depth of field extends farther behind the point of focus than in front of it. How do you control the depth of field you ask? Well, there are three ways to change the depth of field of a photograph: 1) The aperture of the camera, 2) Distance of subject, and 3) the focal length.

The Aperture:

What is this aperture that I speak of? Aperture is what controls how much light the lens lets into the camera (fstop). Aperture and depth of field are inversely proportionate. Therefore, the smaller the aperture the greater the depth of field and the greater the aperture the smaller the depth of field. Get it?

 Taken with an aperature of F1.8                        Taken with an aperature of F10

Distance of Subject:

When deciding what you want to have in focus it is important to remember that the distance your subject is from your camera will affect how much of your foreground, middle ground and background will be in focus. If you’re subject is right in front of your camera and is in focus, everything in your middle ground and background will be blurry,  giving you a shallow depth of field. Whereas, if your subject is in focus in the middle ground, your foreground and background would be out of focus. Likewise, if you focus on a subject in the background, then the foreground and middle ground would be blurry giving you a deep depth of field. It’s all about placement.

Secondly, distance of a subject affects the depth of field differently. When we see depth in a photograph it is really just an illusion that our brain sees when on a picture or drawing. The bigger objects are closer and the smaller objects are farther. So when taking a photograph and you want the objects that are farther away to be bigger and thus giving your photograph a deeper depth of field you have to use a different focal length and aperture. It’s the opposite for if you want something in that’s already larger and in your foreground to be even bigger and everything else smaller, giving it a shallow depth of field. For this you would use the opposite focal length and aperture.

Focal Length:

Focal length is the distance from the lens to the film, when focused on a subject at infinity. To focus on something closer than infinity, the lens needs to move closer to the sensor (or film), which is also why zoom lenses (made of focus on far away objects) are so long. Just like aperture, focal length is inversely proportionate to the depth of field in your photograph. The longer the focal length is, the less depth of field you will have in your photograph. The shorter the focal length the more depth of field you will have in your photograph. A telephoto lens is a very long lens (they are the lenses used mostly in sporting events) and by using this lens you will get less depth of field. A wide angle lens is a less dramatic version of a fish eye lens. By using this lens you will get a very wide shot and consequently a much larger depth of field. But be careful, objects towards the edge of the lens will become distorted, especially depending on how close you are to them.

Taken with a focal length of 38mm                                   Taken with a focal length of 135mm

One cool thing that you can do to extend or shorten the depth of field is zoom in on your subject, then back up from or move closer to your subject all while keeping the your subject the same size by constantly adjusting the zoom. It will be obvious to you how your depth of field is changing. If you move back while keeping your subject the same size your depth of field will look longer and narrower, whereas if you move closer to your subject the depth of field will look more squashed and spread out. Try experimenting with it. It’s fun to see how one shot will come out differently.