Here’s how depth of field works: Your camera’s focal length is a fixed distance between your camera’s lens and your main subject. The aperture setting adjusts the width of the area that stays in sharp focus, both in front of and behind that focal point. F-stops are essentially fractions. They’re based on a lens’s focal length, divided by the size of the aperture opening. A large f-stop creates a small aperture, which in turn allows for a longer depth of field. A small f-stop creates a large aperture that shortens the depth of field.
Now, I’m going to skip the mathematics lecture so we can get to the creative part of our work — I was never great at math, anyways. In reality, there are myriad variables that come into play when working with your camera’s depth of field. Before we begin our f-stop exercise, here’s some good information to know about photography and a few different kinds of cameras you may be using:
For All Camera Users:
- Understand how to manually change the aperture on your camera.
- Use lots of reflected, diffused light – either natural or studio.
- Your camera should be mounted on a sturdy tripod at the same level as the item to be photographed.
- Understand the rule of thirds and how it applies to composition.
- Know that automatic focus, shutter speed and ISO settings can simplify the exercise.
Point-and-Shoot Camera Users:
- Make sure your camera is set to program mode.
- Turn on your macro function. (This is indicated by a flower symbol on many cameras.)
DSLR Camera Users:
Set camera to AV, aperture priority mode.
Mount a macro lens, at least 60mm, to your camera.
Exercise: Experiment with your camera’s depth of field.
To really see the difference between aperture settings and how they affect the depth of field, let’s take three photos of the same setup with three different f-stops — each 2 stops away from the last. For example: F2.8 / F5.6 / F11.
Move your camera closer to your main subject. Do not use zoom.
Choose an area of small detail and center your view on that point.
Hold your shutter button halfway down or manually focus your lens. This will maintain and hold the focus, which is known as “focus lock.”
While continuing to hold your focus, re-frame your image and place your subject where want them to appear in the photograph. For help with a successful composition never forget the rule of thirds. Avoid moving closer or farther away – stay on the same plane to keep your focus point sharp.
When you’re satisfied with your composition, take the photo.
Change your f-stop up two stops and repeat steps 1 – 5.
A shallow depth of field (lowest f-stop) creates the illusion of depth by blurring the foreground and background around a specific point of focus. It is a very effective way to create a feeling of intimacy in your photos. Tip: Focus lock on your subject and recompose the photo to place the focal point just off-center for a more interesting image.
I highly encourage you to play with the settings on your camera and keep track of the changes that occur with each experiment. With some practice and the creative use of backgrounds and props that complement your shop’s branding, you can create dynamic photos.