XtremeCamera

“With today’s incredibly affordable, incredibly good, digital single lens reflex (dSLR) cameras there is no need to learn any photography ‘rules’ because if you set it on Program (P) mode, the onboard computer makes all the decisions for you.” – He that shall remain anonymous. March 2008

A friend that had just purchased a brand-spanking new Nikon D60 said the above quote to me. He had never taken a serious photograph before, and with the first click of the shutter with his new Nikon he was so impressed with himself that he seriously thought about turning Pro.

Well, he is sure to read this, and I won’t embarrass him by identifying him, but there are so many things wrong with his ideas about photography that I still get riled up when I think about it.

Granted today’s dSLR’s have amazing metering abilities, and chances are that if you keep your dSLR on Program mode anything you aim at is going to come out properly exposed, or nearly so. But just because you haven’t managed to under expose or over expose a photo it doesn’t mean the photo is anything more than a snapshot. It takes years to learn to create good photographs, and it always will.

In today’s tutorial I want to touch on just one aspect of photography; Aperture. Simply put, the aperture setting you choose and the shutter speed you choose are the biggest factors in determining the outcome of your photograph. They work hand in hand, and learning to master them both will give you the power to control what you create more than any other photography skill.

Aperture isn’t just an Apple software application

Aperture controls the depth of field in your image. The depth of field (DOF) is the space that remains in focus between the main subject in the photograph and everything in the foreground and background.

Using the widest setting light (the smallest number on the lens, i.e., f1.8) lets in the most light, yet also produces the shallowest depth of field. Stopping down (using larger numbers, i.e., f8, f16) restricts the amount of light you let in, yet focuses the light so well that the depth of field increases and whatever is in front of the main subject or behind stays in focus.

For instance; say you wanted to isolate someone in a crowd. You want to make sure that the viewer of your photo knows that the person you are photographing is the main subject. In such an instance you would try to use the widest, most open, aperture that you can. Seeing as how this will limit the area around your subject that remains in focus using a wide-open aperture focuses on your subject and everything else is focused more softly. Of course, this is a very simple explanation, a very basic understanding of using a wide-open aperture setting, but I hope you get the idea.

A wide-open aperture, or any setting in the wider range, brings with them a narrow field of focus. Simple, right? And naturally, the opposite is true. Using a smaller aperture focuses the amount of light you allow into the camera, which in turn creates a sharper image with a wider area of space that remains properly focused.

For instance; perhaps with the same shot described above your intention is to show all the people around your main subject in sharp focus. To do this you want a larger area of focus, you want to use a smaller aperture setting. The smaller your aperture the more depth of field (DOF), the more DOF the sharper everything around, in front, and behind your subject becomes.

To really see the difference this can make, try this experiment the next time you go cruising for snapz.
Place an object, or person, whatever you want, about 20 feet from you and your camera. Place another object of about the same size 10 feet in front of your camera and 10 feet behind your subject.

Look through your viewfinder and compose your shot. Place your main subject in the middle, allowing the foreground subject to fall to the lower left of your image and the further back subject to fall in the upper right of your viewfinder. Focusing only on your main subject, set your camera on “A” mode, meaning Aperture Priority (which allows you to choose the Aperture and your onboard computer tries to use the correct shutter speed to compensate) and set the first shot to capture using f8, usually the middle of the road aperture setting.

After you fire off that shot set your aperture at the widest setting, depending on your lens that could be f1.8 or f3.5. Line up the shot exactly was before, remaining to focus on the main subject only. Click the shutter.

Now set the aperture to the smallest opening, for many lenses that will be right around f16 or even f32. As before, focus on your main subject and click the shutter.

Now, run into the house, plug your camera into the computer and transfer your photos as you normally would. Bring up all three images on your display and set them side by side (its okay if you have to shrink your images down on the screen) and carefully look at them…

If you did this right you’ll see that in the first shot, the f8 or middle aperture setting you have a baseline photo. Notice what is and what is not in focus in front and behind your main subject.
Now look at the image where you shot with the widest aperture setting. Notice how your main subject remains focuses and sharp but the subject 10 in front and the one 10 feet behind are much more out of focus than the shot your using as the baseline shot. With more light comes a softer focus, a narrow DOF…

Now do the same with your smallest aperture shot. Here you should notice that the main subject remains sharp while the subjects in front and behind are much more focused than the shot you took with the aperture wide open. This is the magic of the aperture.

Every serious photograph (serious meaning an attempt to create a photograph, not a snapshot) needs to have many things taken into consideration before the shutter is clicked. The most serious to consider is aperture and shutter speed. What I’ve written today should give you a bare inkling of how the aperture works, but if you do the test as describe above you will instantly recognize the power of “depth of field”.

Next time I’ll take a look at shutter speeds. After that I’ll combine both and give you some pointers on how to effectively use both aperture and shutter speed to create the photograph YOU want, not the one your onboard computer wants. Trust me, its makes a huge difference. After all, a machine is a machine; it’s the people that control them, not the other way around. Hey, I know! Next time I’ll even bring some of my own photos to illustrate my point.

Till next time!

Steven McBride