Thematic Thursdays - Depth of Field (pt. 1)

Hi There!

Today's photography focus will be the first of a two part series centered around depth of field. The term depth of field (in photography) refers to the amount of the picture that is in focus. A large depth of field occurs when the entire picture is sharp, whereas a small depth of field is when a certain subject is emphasized by blurring the surroundings. I'll be talking about shallow depth of field in this post.

Utilizing a shallow depth of field often results in striking photographs. This technique is especially useful for single subject shots, such as portraits. I also like to employ it when I want to emphasize certain nature and architecture subjects, or macro photography. 

The most common way to achieve a shallow depth of field is by understanding aperture. Aperture is basically the hole in your lens - the smaller the hole, the higher the f/stop (how aperture is measured on your DSLR). This can be confusing at first, but an easy way to remember is to know that the higher the f/stop, the more of your image will be in focus. 

The most common (for me, anyway) shallow depth of field technique involves using a low f/stop and then placing the object I want to emphasize in the foreground, in focus.

shot with a Nikon D5100
ISO 640  38mm  f/5.0  1/800s

In this shot, I wanted to focus on the chain-link fence to draw the eye to the scrap of paper that had been tied to it. Blurring the background ensured that the focal point of this shot would be where I intended.

This is also an extremely effective way to shoot portraits. I'm not much of a portrait photographer, but I did take this shot of a family friend's pet that illustrates the impact of shallow depth of field:

Alternatively, this technique can also be used to highlight an object in the out of focus background of the photo. This may seem counterintuitive, but here is an example:

shot with an Olympus E-P3
ISO 800  42mm  f/5.6  1/1600s

Although the tall grass in the foreground is in focus, the subject of this shot is the very dominant, out of focus barn in the background. 

On the opposite end, sometimes it is more visually arresting to place your object focused in the background, while leaving the foreground blurred, as in these photos:

shot with a Canon Rebel XT
ISO 640  55mm f/5.6  1/1250s

shot with a Canon Rebel XT
ISO 400  28mm  f/4.0  1/1600s

Here is a shot from the same perspective, but different focus:

shot with a Canon Rebel XT
ISO 400  28mm  f/4.0  1/1600s

Something to keep in mind when taking pictures with a shallow depth of field, or smaller aperture: remember that the higher the aperture, the smaller the hole in the lens - you will need to make up for the lack of light somehow. The most intuitive thing to do is to lower your shutter speed, just be mindful of this in low light situations - you may need a tripod to minimize blurring, or some other source of light  (like an external flash).

Experimentation is key! I like to take the same subject and shoot it in many different ways. I can't recommend this exercise enough. The more familiar you are with your equipment and your viewpoint, the better your pictures will get.

Thanks for stopping by!