Every photographer dreams up their own way of tackling issues revolving around their medium of choice. One of the most common issues that amateurs and professionals alike face behind the camera is determining what aspects of an image to cast in focus or out of focus.
You’ve probably already developed a technique to adjust your depth of field when necessary. But did you know that there are actually three separate aspects that play into an image’s depth of field? Jeff Rojas presents some basic optical information that fully explains what a photographer can do to manipulate focus and how that impacts the final photograph:
Most photographers choose to adjust depth of field by simply adjusting their f-stop, or aperture. Increasing the width of a camera’s aperture allows more light to hit the camera’s sensor and narrows the area of focus within a scene. Likewise, using a higher f-stop can portray details near and far in crisp, clear detail.
The distance between a lens and its area of focus plays a significant role in what areas of an image appear in focus. This is because the focal length of a lens directly impacts the user’s viewing angle. Smaller viewing angles result in smaller areas of focus; therefore, the contrast in depth of field using a macro lens is much more dramatic and visible then that of a wide angle model.
Perhaps the most simple way of affecting an image’s depth of field is to simply reposition the camera in relation to the subject. More of a subject will appear in focus the farther away it is from the camera’s lens. Conversely, bringing a subject closer to the camera will result in it appearing less in focus. The same concept applies to the elements behind your subject – the farther away the subject and camera is positioned from a background, the less defined it will appear.
One of the building blocks to creating a great image is the ability to master depth of field. Understanding different coping strategies and applying each when appropriate is crucial in the growth of any photographer.
“There’s actually a pretty complex formula that you can use to calculate your focus area of your image, but I absolutely don’t expect you to remember it or utilize it; we’re going to keep things simple.”