Photography Basics: Exposure at a Glance

Welcome to my basics series! Although a lot of my posts involve DSLR shooting, since that’s what I primarily use, I wanted to create some articles that would be universal to photography with almost any digital camera. For those of you who don’t know, DSLR stands for Digital Single-Lens Reflex, and it refers to the way the camera uses a single lens and a mirror to process light into images. At this time, I’m more interested in the art of taking photos than in the more technical details of how a camera works; I’m planning on writing some posts in the future about different types of gear when I start getting ready to upgrade my equipment, but today is not that day. Today we’re talking about exposure, which is the foundation of photography no matter what kind of camera you’re using.

But I won’t leave you tech fans high and dry. If you want to know more about the differences between types of cameras on the market, here is a Wikipedia article that talks about DSLRs, traditional digital cameras, and the newer mirrorless system cameras. Enjoy!

Exposure is basically how bright or dark your image appears. It’s something I’ve touched on before here and here, but so far have not discussed in detail. It’s one of those things that seems simple in theory but can be tricky to master.

I’m going out on a limb here and guessing that most beginner photographers shoot in Auto, or whatever their camera’s approximation of Auto is. It’s easy and safe, and most cameras will probably produce decent pictures in Auto. There’s nothing wrong with that.

But what if you want to do better than decent? Well, then it’s time to get out of the safe zone that Auto mode provides and start taking control of your photography. This is a process, by the way–don’t be discouraged if your pictures are bad at first. Set aside time to practice and you’ll eventually see your hard work pay off.

This was taken on auto at sunset. It’s not a bad photo overall, but I prefer the manual version below.
This one was taken in manual, just a few seconds after the auto picture. It is a bit darker, but I feel like the sunset looks much deeper. Honestly, I probably should have gotten in place a few minutes earlier.

The first step in the process is to dig out your camera manual and figure out how to change the settings. You’re looking for three things–shutter speed, aperture (or f-stops), and ISO. If you don’t have the manual, look for your camera model in a search engine and see if one is available to view online or download. If you’re shooting with your smartphone, consider an app that will give you that level of control over your phone’s camera. Open Camera (Android) or Halide (iOS) came up after a quick Google search for me; I don’t use either of them, though, so I can’t tell you how well they perform. You’ll have to try them out on your own and then come back and tell me about them. (I’m 100% guilty of leaving my phone in Auto all the time; I don’t take pictures with it all that often.)

Step two is learning how these three elements interact with one another to create an image. This one’s going to take some practice. For now, we’ll just go over what the elements are.

Shutter speed–In a digital camera, shutter speed refers to the amount of time the camera’s sensor is exposed to light. In a nutshell, high shutter speeds are good for bright places, while slower ones will allow more light to reach your sensor when it’s dark. But wait, there’s more! Your shutter speed will also determine how much motion is in an image. A high speed will allow you to capture subjects in motion while lower speeds introduce blur. Shutter speed is usually measured in seconds or fractions of a second. We’ll talk more about this next week.

This was shot at a fairly high (I want to say 1/250 but of course I didn’t write it down) shutter speed. As you can see, the water in the fountain is “frozen” midair.
Same fountain, same time, the big change was a much slower shutter speed. I also had to adjust aperture to keep from overexposing the shot. You can see the motion of the water here, and the background is brighter as well.

Aperture–We’ve talked about aperture before, and we will again. You can’t have a complete understanding of exposure without learning about all three elements, and I feel like this one allows you a great degree of creative control over your photos. Aperture is the opening in the lens of your camera (and different lenses will allow you to achieve different apertures, which is another bonus of a DSLR or a camera that allows you to switch out lenses); it’s measured in F-stops. Small numbers are wider openings, which allow more light to pass through the lens. Large numbers are smaller openings and let in less light. But that’s not all! Your aperture also determines your depth-of-field, or which parts of the photo are in focus. Large numbers are good for landscape photos or pictures where you want everything to be the same level of focus. Small numbers are good for softness or artistic blur.

This field of sunflowers was shot at a high f-stop (I want to say 16 or 20), so all of the flowers have about the same amount of focus.
This sunflower was shot at an aperture of F 1.8, the widest I can produce at the moment. The image in the foreground is fairly sharp and the soft background makes it stand out even more.

ISO–The ISO determines how sensitive your camera is to light. Lower numbers are less sensitive, while high numbers are more sensitive. Like shutter speed and aperture, ISO is also a twofold element. A high ISO will allow you to take photos in darker environments, but it also introduces noise to your photos. I don’t care for noisy photos, and I had a serious problem with cameras taking very noisy pictures in low light. So taking control of this was a big deal for me. I tend to shoot with a low ISO and only change it if I can’t get the shot I want by altering my shutter speed and aperture.

Here’s an example of a photo with noise. I shot this on Auto a long time ago. See all the speckles in the background? That’s noise caused by a high ISO.

When you’re getting ready to take a photo, exposure is one of the first things you need to consider. It’s not just how bright or dark you want your image to be, but also how you want to capture motion, depth-of-field, and the amount of noise you’re willing to put up with to achieve your desired shot. It’s a balancing act. Over the next few weeks, I’m going to try to show you how to manipulate all three of these elements so that you can find the balance in your own photography.

Thanks for reading, everyone! Please come back next Friday for a more in-depth look at shutter speed. I’m working on putting some really cool stuff together for you. In the meantime, you can follow me on Facebook for more pictures, articles, and other goodies.



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