Photography 101: What is Exposure?
If you are new to photography, then the term “exposure” might still be pretty confusing to you. In this Photography 101 guide, we’ll try our best effort to simplify it so that you can move away from that Auto mode as soon as possible!
In the upcoming guides, however, we’ll talk deeper about the three main components of exposure so that we won’t stop too much on the nuts and bolts of them right now.
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What you need to understand about exposure is that it is the way your camera measures light, and why is this so important? Well, it is important that you can tell your camera how you want it to behave depending not only on the light in front of it but in accordance to what you want to achieve with your photos.
Camera manufacturers have done a fantastic job by building those auto modes in our modern-day cameras. Really, they are impressive, and they are a good way to go if you want perfectly exposed photos each and every single time. Now that ends up being quite boring, and that’s why being able to control how your camera one towards light is so important.
Exposure is built out of three main settings. The first one is called ISO, and it basically controls how your camera’s sensor behaves under pretty specific lighting conditions light shady indoors or bright sunny days. The second exposure-related value is Shutter Speed or the amount of time you’ll allow your camera to feed upon light.
And last but not least, the scariest value for the beginners, Aperture. This value, however, is pretty friendly, and simply controls the amount of light that will pass through your lens into ultimately hitting your sensor.
So far it doesn’t sound too complicated right?
Here is the 101 photographer’s workflow for measuring light. The first thing that you’ll need to do from here on is to see how light is behaving around you, so you can tell your camera how it should interpret that light. Secondly, you’ll have to decide how fast or how slow your shot will be, depending on the purpose of it. And last but not least, you’ll need to decide how much light your camera will chug.
The combination of values is what we photographers know as the “exposure triangle”, which is just rhetoric or illustrative way of saying that you can achieve the same exposure value via multiple exposure decisions.
Therefore, if you move one setting, then you’ll need to compensate both or just one of them depending on what you want to achieve. Practising is the only way for fully understanding how these three values behave among each other.
So, how’s exposure measured?
Just like distance is measured in meters or weight is measured in kilos, light is measured in stops. If you look carefully through your viewfinder, you’ll see a small scale that runs from negative values to positive values, leaving a bright and nice zero in the middle. It usually looks something like this:
What this scale is telling us is that as long as the measurement points far from the zero light will be registered in more or fewer quantities. Perfection (zero) seems like the obvious choice, but sometimes we want our photos to look a bit more dramatic (briefly underexposed) or bright and joyful (little-bit-overexposed).
Each exposure element has its own standardized numbers; and each change in value increases or decreases a stop of light. Here is where it starts to get confusing, and if that wasn’t bad or complicated enough, you could move 1/3, 2/3, or a 1 full stop of light. But we won’t cover those in this book so don’t worry. What you need to understand is that these values need to coexist in a logical way that corresponds to your intentions.
In the following articles, we’ll explain further how each ISO, Shutter Speed and Aperture will affect that measurement. But from here on you’ll have to make yourself a promise, photography is about practice (daily and regular practice), so don’t expect to master all this information simply by reading our friendly photography guide!
*Image by Daniel Peters / Photoblog