Join Ben Long for an in-depth discussion in this video Understanding exposure, part of Introduction to Photography.
- Exposure is a word that is used a lot in photography. We'll talk about getting a good exposure, or we might say, "The exposure is good in this image." Or sometimes we might say the exposure is bad in this image. The size of a roll of film is measured in exposures. So, is exposure simply another term for an image or a photo? Sometimes, but not always. The good news, is that you're already actually experienced in the idea of exposure, just from using your eyes. In photographic terms, when we speak of exposure, we're usually simply referring to how much light the camera is capturing.
Your camera is just like your eyes, in that it requires a certain amount of light to be able to see detail in a scene. Now, you already know that when there's not enough light, you can't see. Your camera has the same problem. From time to time, you might also have encountered a situation with too much light, which also makes it hard to see. Again, your camera has the same problem. So, at the simplest level, exposure is simply a measure of how much light the camera is capturing. Now consider this image of me that you're watching right now The camera is currently configured with exposure settings that are capturing an image that is this bright.
If we adjust the settings, we can brighten the image, or darken it. We refer to that as changing the exposure. Another way to think of it, is that the camera's image sensor is getting exposed to more or less light, depending on our settings. As those exposure settings change, the final image gets brighter or darker. So what's the correct level of exposure? There's rarely a single correct answer to that question. It depends partly on what it is that you want to see in a scene. For example, with the exposure settings that we're currently using, you can see good detail on my skin, but look at this dark area, the area that's in shadow.
You can't see anything over there. And you may think that's simply because there's nothing to see, but there is. But not with our current exposure settings. If we change the settings on the camera to brighten the scene, we can bring out the details in that shadowy area, but in doing that, we lose the details in these bright areas. Details that we were able to see before, they have now gone out to complete white. These areas that were completely dark, are now, are now visible.
That's a garden gnome with sunglasses... When we speak of an image having a good exposure, we're usually referring, simply to how well we can see the important details in the image. Are they lost in shadow? If so, then we might say that the image is under exposed, it didn't get enough light. If details are blown out to complete white, we say the image is over exposed, there was too much light. As you study exposure more, you'll learn that it has other impacts on your image. From color reproduction to what, in your scene, is in focus.
But for now, all you need to know, is that you control the overall brightness of your final image by adjusting your camera's exposure controls. As you change exposure, the image will get brighter or darker, and different details in the image, will become more or less visible.
Then it's time to take to the field and examine the rest of the factors that influence the quality of your photographs, including light metering, focus, composition, and flash. Ben also introduces techniques for shooting portraits and shows what you can do with an image editor in post. Last but not least, he'll provide a roadmap for learning more with the lynda.com extensive library of photography training. The path to becoming a better photographer begins with the first step. Start here!
- Exploring cameras and lenses
- Understanding media
- Controlling exposure
- Composing with autofocus
- Shooting portraits
- Understanding form and geometry
- Exporting and editing digital images