Photography is light. Every time you press the shutter there are a series of actions that take place inside your camera, resulting in an image. None of this would be possible if there were no light.
Today I’m going to talk to you about light triangle. It is a very important concept and if you want to get hold of the manual and semi-manual mode and handle them with ease, you will need to have a good understanding of the 3 components of this triangle. I would say that they are the most influential factors in how the final photograph is going to be.
The three elements of the Triangle of Light
The three elements that make up the famous triangle of light are the ISO, aperture, and shutter speed.
Most of the readers of this blog know what each of these factors is, but in case you are a laggard, I will explain them very briefly:
- ISO: is the sensitivity of the sensor to light, the higher the ISO value we choose, the more sensitive the sensor of our camera will become to light and therefore it will capture more light.
- Opening: It is the size of the diaphragm, that is, the hole that is inside the objective or lens, and that allows light to enter. The larger the aperture, the more light will enter and be recorded by the camera.
- Shutter speed (or shutter speed): It is the time during which the camera is kept open registering the light or photo. They are generally fractions of a second, the duration of a shot, but can be longer. In fact, at slower shutter speeds, more light enters the camera.
The mixture, to a greater or lesser degree, of these 3 factors is what gives us the final photo. And what is more important: each change in any of these 3 factors will impact the other 2, which means that, in manual mode, you cannot modify one factor of these 3 without taking into account the other 2. This, fortunately , the camera already does it for us in automatic mode and even in semi-manual modes, but in manual mode we are the ones who control everything.
How to Play with the Triangle of Light
Let’s see. Capturing a photograph is actually capturing the right amount of light from what we want to photograph. Do we agree on that? Ok, so now I want you to imagine yourself in a room with a closed window. There is no source of light other than that window, which is initially closed. Also, and to make it more fun, imagine that you are wearing sunglasses. do you follow me
If we wanted to illuminate that room we would open that window, but if we wanted to have the room much more illuminated, we could enlarge that window, right? It is true that a larger window would give us more light. Do you know what that is in photography? It’s called the opening.
Now imagine that we don’t want or can’t make the window bigger, but we still want light to come in. Well, we would start by opening the window, but the longer we leave it open, the more light would enter (with the slight difference that in the room the light is lost, not accumulated, but in the camera the light accumulates and is guard). Well, this is the closest thing to shutter speed. If in an SLR camera in «M» mode we choose a shutter speed of 2 seconds, twice as much light will enter than if the speed is only 1 second.
Remember that you are still wearing sunglasses since we started the example. Those sunglasses symbolize the ISO value, that if we have it low in a camera, only enough light will enter. What would happen if, with the window open, you took off your sunglasses? Simply your eyes would receive more light. The same thing happens when we raise the ISO to high values (with the small difference that, in SLR cameras, the ISO sometimes leads to a bit of noise and grain in the photo).
Master the Triangle of Light
By mastering each of these 3 factors separately, you will learn to control them as a whole. If you want a little trick which I always recommend for those who are taking their first steps in manual mode: use the semi-manual modes of your camera and learn from observation. The camera is wise, in Aperture Priority mode (“A” Mode on Nikon, “Av” on Canon) what you can control is the size of the aperture. Try changing that value and see how the camera automatically changes the other factor, the shutter speed. If you put a small aperture, f/16 for example, the camera will choose a rather slow shutter speed, if you choose a huge aperture, like f/2.8, you will see that the shutter speed will be faster, and so on. You can also try Shooting Priority mode (“S” on Nikon and “Tv” on Canon), only the other way around.
Side effects
It should be noted that each of the 3 factors described above has secondary effects (sometimes that is what we are looking for). Aperture has a direct impact on depth of field, ISO influences how much grain/noise will appear in the photo, and shutter speed influences how we capture action or movement).
And here with today’s topic. You have learned something? I hope so. From then on, it should be able to challenge the light in your photos and tame it to get the photo you want. If there are things missing to clarify, ask me and I will gladly explain them to you.