You focus on your friend, and the parked cars and fence behind her look just as sharp as she does. A softer background would keep the eye on her. The zone that looks sharp is called depth of field, and it is a topic in the second session of Digital Camera Basics.
What Makes a Background Blurry?
Four things shape it: the aperture you choose, how close you stand to your subject, how far the background sits behind your subject, and how much you zoom with your lens.
Adobe’s guide to depth of field names aperture, focal length, and distance to your subject as the main factors. A wider aperture such as f/2.8 or f/4, a longer lens (100-200mm), and standing closer to your subject (as long as the subject isn’t close to the background) help to make the background less focused.
How Does Aperture Change the Blur?
A wider aperture gives a shallower depth of field, so the background softens. A wider aperture has a smaller f/number: f/4 is wider than f/11. The apertures are actually “ratios”, or fractions, so f/4 could be thought of as 1/4 and f/8 as 1/8. That makes the larger/smaller aspects of aperture easier to understand.
The widest aperture of your lens may also vary as you zoom. Many lenses have a variable maximum aperture where the widest opening will decrease as you zoom to longer focal lengths. Fixed aperture lenses (which are more expensive), eliminate this complication. If you don’t have a wide aperture as a possibility, stepping closer, or extending your zoom can still be very helpful. Opening the aperture also lets in more light, so it may be beneficial to adjust the ISO or shutter speed as well. Every setting you change affects the others, which is why Eliot teaches aperture alongside ISO and shutter speed.
Does Distance Matter as Much as Aperture?
In many scenes, yes. Standing closer to your subject and moving your subject farther from the background both increase the blur, even when the aperture stays the same.
Is your subject leaning on a wall? A wall right behind her may not show blur at any aperture. A few steps of space between the two can do more than an adjustment on the aperture scale.
What Is the Trade-Off With a Soft Background?
The softness that melts a background can reach your subject too. If you photograph a face from close up at a wide aperture, the eyes may be sharp while the ears are not. How much of your subject do you want sharp? Thinking about that before you press the shutter is what depth of field is about. It may not be measurable before you shoot, so perhaps try a couple of apertures to see what offers the best result.
Eliot has noticed that students often appreciate the emphasis that shallow depth of field can provide. It makes the subject easy to pick out, and sometimes softer backgrounds add a nice ethereal effect.
How Does a Digital Camera Class Teach Depth of Field?
Digital Camera Basics is a digital camera class in Washington, D.C. that runs three live evening sessions over Zoom. Each lasts two hours, the class is limited to six students, and the $189 fee covers all three. The first session covers relevant camera menus, ISO, shutter speed, and aperture. The second introduces depth of field and exposure compensation along with a review of participant photos.
Eliot shows menus and settings for each camera, so you learn where to find all the relevant aperture controls. The class draws on his wide-ranging teaching experience.
Where Can You Take a Photography Class for Beginners Near Washington, D.C.?
Washington Photo Focus offers a photography class for beginners in DC over Zoom, and some classes meet in person at locations around Northern Virginia, Maryland, and D.C.
Students can also find digital photography classes in Northern Virginia and online digital photography courses in Maryland on their own pages. If a group schedule does not fit, private photography lessons let you work on aperture and distance one-on-one, by video call or in person.
Frequently Asked Questions
Does a lower f-number mean more blur?
Yes. A lower f-number is a wider aperture, which gives a shallower depth of field and a softer background, all else equal.
Do I need a camera or will a phone suffice?
Classes use cameras, because phones do not have all the controls that cameras have. A DSLR or mirrorless camera works best, and any camera that lets you set ISO, shutter speed, and aperture can work.
Does my zoom lens limit how blurry the background can get?
It can. On many zoom lenses the widest aperture gets narrower as you zoom in, so distance matters more.
Which session covers depth of field in Digital Camera Basics?
The second session emphasizes aperture, depth of field and exposure compensation, with a review of participant photos. Aperture is covered in the first session.
Want to see which class fits you or have further questions, email Eliot at eliot@washingtonphotofocus.com, and he will get right back to you.
