![]() So instead of the log or the bear…substitute your car or group of people and visualize the outcome. Here you can clearly see the affects to the depth of field behind the bear. With the aperture set at f/25 you’ll see that the DOF is now very deep, and that both the background as well as the foreground are relatively in sharp focus.Īnd in the example with the bear statue, the focal length remains the same, 105mm, as well as the distance that the camera is positioned…all I did was alter the aperture. With the aperture set at f/2.8 you’ll see that the DOF is very shallow, and that the area of blurriness extends behind as well as in front of the focal point. In the first, with the log, the focus point was about 10 feet up the log, and the focal length was 100mm. Pretty darn cool, huh? And a very easy concept to understand. ![]() And you can change any of them!ĭo the same example above, but this time only change the focal length.ĭo the same example above, but only change the aperture.ĭo the same example above, and now fiddle with all three variables. The cool thing about understanding this technique, is that ALL of these 3 variables are in your control to affect the Bokeh. You will see that the further back you are, the more "in focus" the background appears. You have 5 shots that you can now compare.all have the same focal length, and the same aperture.but the changing variable is that you are further back with each consecutive shot. Take two more steps back, re-focus.take a shot. ![]() Take two steps back, re-focus.take a shot Now.don't change anything on your camera!!!! ![]() Make sure there is some distance between your subject and the background. Zoom your lens to its maximum focal length.like 300mm, dial in the widest aperture you can (small f number), and get as close to your subject as you can and still be able to focus. Here's a practice exercise for you- set something up in your front yard on a table (or in your kitchen), like a statue or bird feeder. Three key factors affect depth of field, as well as that “blurry” background or foreground. Here are a few key factors that you can review… There is no magic formula persay, but based more on experience, and understanding of the "relationships". The depth of field is something that "YOU" choose creatively, that enhances your photos, and it is dependent on the amount of experience that you have with your camera and lenses. Playing around with the "Variables" affecting Depth Of Field is very fun!!! Play around with the depth of field calculator to see what effect the different parameters have on depth of field. When using a macro - relative long focal length with very close subject - you get depth of field that is razor thin even at F22.Ĭase in point, at F22, 100mm with a subject 6 inches away, the depth of field is only 0.3 inches! Conversely at F22, 100mm with subject 6 yards (18 feet) away, the depth of field is 8.8 feet, or nearly 3 yards. Longer focal lengths isolate subjects better than short onesĬloser subjects are easier to isolate than farther ones. I could show you F22 shots that have a razor thin depth of field, and F3.5 shots where everything is in focus. It is only after those parameters have been established that aperture should come into play. The bigger factors are focal length, distance to subject, and distance from subject to background. That can actually hurt image quality due to image difraction.īelieve it or not, aperture has very little relevance on DOF. However, do I need the smallest aperture? Or will one of the intermediate f-stops work? If I don't use a small enough aperture, only my focus point will be sharp when I shoot the picture. so I can see the back, one side, and top of the car from where I'm at). E.g., something like, "use f-stop X for a depth of field of around Y".įor example, say I wanted to take a picture of a car, standing diagonal to it, and up on a chair (i.e. But at this point, I'm hoping for a general rule of thumb. So my question is: how do you determine what f-stop to use? I'm sure there's a formula that relates depth of field to f-stop and other lens attributes. In short, I generally don't use any of the "middle" f-stops. In other words, if I want to focus on a single point, I set my camera's f-stop to the smallest value (largest aperture) if I want sharpness at multiple depths, I crank the f-stop up to the largest value (smallest aperture). Using this shallow understanding of the concept, I usually set my apertures to one extreme or the other. larger f-stop) means greater depth-of-field, and likewise, a larger aperture means lesser depth-of-field. I understand the general idea that a smaller aperture (i.e.
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