Handle Your Camera Like A Boss | Lesson 2 | The Exposure Triangle
Photography is all about the light. So learning how your camera reacts to light is probably THE most important technical skill you can master. You can take a picture of the most boring thing on the planet, but if the light is good, it will make a fantastic image. The opposite is also true. You can have wonderful subject matter but if the lighting is bad, or you blow the exposure, the image is ruined. Learning how to adjust your settings to get exactly the exposure you want is crucial to your art. And yes, you ARE creating art. Family heirlooms and all that. And even if your family photos are art, they’re still crazy important. Think of all the cruddy images you have on your phone or on your computer that you keep even though they’re awful. Why do you keep them? Because they’re links to the most cherished people in your life and you love them in spite of the fact they’re a little blurry. Just think how much you’ll love your photos once you learn what you’re doing!!!
So here we go--remember, it’s all about the light!
“The Exposure Triangle” sounds like the name of the latest Matt Damon movie, but in reality this is the term used for the three fundamental elements of exposure, and it’s really important that you understand how it works. I’m going to explain it by using a metaphor. Imagine yourself standing out in the rain, collecting water in a bucket. You are attempting to fill up your bucket just enough--too much and it will overflow, and too little and you’ll still be thirsty. The perfectly filled bucket equals a perfectly exposed photo. Achieving the best exposure is pretty much like collecting rainwater in a bucket. You want to make sure that you collect neither not enough (underexposed images), nor too much (overexposed images) water.
There are three factors involved in getting the water level in your bucket just right (or getting a proper exposure):
•how heavy the rain is (ISO)
•how wide your bucket is (aperture--also called f stop)
•the amount of time you’re out standing in the rain (Shutter Speed)
All three work together to control how much water fills up your bucket (or how much light is allowed into the camera). The secret is that you can use various combinations of size, duration and quantity to achieve the best results. For example, to collect one gallon of water, you need less time if you have a really wide bucket. On the other hand, for an equal amount of time, you will collect less water if you use a really narrow bucket. By learning how each element of the triangle works, you will be in control of the variables and you’ll be able to get the perfect exposure.
(We will cover ‘perfect exposure’ and your camera’s light meter in the future--it’s too much to get into today and your brain will probably melt.)
Got it? Ok. Let's get a tiny bit more technical now.
ISO - does nothing more than control the amount of light being let in. There are generally 5 levels of ISO, 100, 200, 400, 800, and 1600 on consumer grade cameras. Pro-sumer and pro cameras have more ISO options. The higher the number, the more light is allowed in. If your ISO is the same as rain, a low ISO is a light rain and a higher ISO is a heavier rain.
Aperture (f/stop pronounced "eff stop") - is the size of the lens opening; the lower the number, the more light is let into the lens. For example, an aperture of f/2.0 lets in more light than one of f/8.0. If your aperture is the size of your bucket opening, then a wide bucket will gather more rain than a narrow bucket will. Aperture is also where it can get confusing. A larger aperture is actually a LOWER number. "Close up your ap" means to use a higher f/stop, letting less light in.
Another way to explain aperture is this: Your aperture is like your pupil. When the light is low, your pupil opens up in order to let more light in. Or the opposite, when you step outside on a bright day, your pupil contracts to decrease the amount of light it lets in. The f/ stop number is like the size of your iris (colored part of your eye). Your iris is small when your pupil is large when you need more light, and in turn, your iris is large when you are in a bright situation and your pupil contracts.
I don’t know a photographer alive who hasn’t had serious problems remembering this. I’m still not exactly sure unless I stop and think about it for a few seconds. Just know that it’s normal and move on, eventually it will all click. ;-)
Aperture selection is the key to getting a subject in focus and the background blurry. If you are shooting at f/2, your focal plane is very thin. Meaning, there will only be a small portion of the image that will be in sharp focus; the remainder of the frame will be blurry / out of focus. The contrary to this would be an aperture of f/8 or f/16, where you will have a larger area that is in focus. This is commonly referred to as depth of field. Focal planes go front to back. Think of a focal plane as 2 panes of glass. Only what is between the two panes is in focus. When you have an aperture of f/2.0 your panes of glass are much closer together than they would be if you selected an aperture of f/8. If you are having trouble getting the proper focus on your subject, try closing down your aperture. This will increase the size between your two 'window panes' and increase your chances of catching your subject between those two panes. There are two factors in creating your focal plane; aperture and distance. The closer you are, the smaller your focal plane. Move back and your focal plane gets wider.
Shutter Speed - controls the amount of time that light is allowed to enter your lens. The faster the shutter speed, the less light hits the sensor; conversely, the slower your shutter speed the more light is let in. Think of your shutter speed as the amount of time you’re standing out in the rain with your bucket. If you’re out for a long time, you’ll gather more rain than if you just stood out there for short time.
Your shutter speed is what stops movement, so an appropriate shutter speed is crucial to getting a sharp image. One of the most common beginner questions is "why is this image blurry?" and most of the time the answer is "your shutter speed (SS) was too slow.” When you use your camera on auto mode and let the camera decide your settings, a blurry image is a common result. This is because the camera has ‘maxed out’ its ISO and aperture settings and still needs more light in order to get a proper exposure. The only way to get it is by keeping the shutter open for longer. If you have a fast moving subject, the longer the shutter speed, the blurrier the object will be. When shooting photos of people, and especially with children, it's best to keep your SS at 1/125 or faster. I wouldn’t dare try shooting a toddler at anything lower than 1/250 and I try to go higher than that. If your shutter speed is too slow, you risk motion blur either from your subject moving, or from you inadvertently moving the camera while shooting (something I do all the time).
With your newly gained knowledge, go out and play with your camera a bit. Try shooting a moving subject with different shutter speeds to see what happens. I like to practice on a ceiling fan for this one to see what happens when you slow the shutter speed way down. Try out different apertures with a line of apples on your table. See which aperture lets you get all of them in focus. And for ISO settings, see which setting gives you the optimal amount of light for shooting in a lower light atmosphere.
Have fun and be sure to come back for Lesson #3: "Shooting Modes"!