The Exposure Triangle
One of the most important aspects of photography if you're looking to go beyond a point and shoot camera is understanding the exposure triangle.
Understanding this is the key to building a solid foundation in photography, and producing some great creative shots.
It is the relationship between the aperture, shutter speed and ISO, and how a change in one will affect the other two.
To gain an understanding of the concept, it's easier to use an analogy, so consider a window on a house with curtains, and yourself inside with a pair of sunglasses.
This is your camera.
The aperture is the curtains, if they are open, they will let in more light, if they are closed, they let in little light.
The shutter speed is how long these curtains are open for.
The ISO is you, and how sensitive you are to the light coming in, on a camera it is your sensor.
Let's say that you want a certain amount of light into the room, say an amount of 10.
You have your sunglasses on, and set to have your curtains half open for a period of 1 second.
This gives us 10.
Next, we want the same amount of light (10), but for whatever reason, we only want the curtains to be open half the time, but our sunglasses still need to be on.
Therefore, to give this same amount of light, our curtains will need to be fully open.
For the next scenario, the sunglasses need to be off, but we still want the same amount of light to enter the room.
Therefore, we can either alter the amount of time the curtains are open for, the amount the curtains are open, or both.
The camera is the same, and by adjusting these three elements, we can control how light enters the camera and thus the results.
So if we still want the same amount of light in, why the need to change the settings? Well, the simple answer is it depends on the type of photograph you want to produce.
If you want to take an action shot of a sport, or dog running, then you will want a very fast shutter speed to clearly capture the action.
Because your shutter speed is fast, to get enough light into your camera to take the shot, you will need to set your ISO according to the conditions (if outside on a bright day, then you need a low ISO number, this means the sensor isn't greatly reactive to light, which is what you want for outside photography.
Therefore, to get the light you need, your aperture needs to be open more to allow the light in.
In contrast, if you are photographing at night, you will need a high ISO number to make your sensor receptive to light, your aperture to remain open (as your eye would), and probably your shutter speed to be slow, perhaps a couple of seconds.
Of course, there's a multitude of settings you can set your camera up depending on the light and what you are aiming to do, but this same logic applies to every camera, no matter what; a top of the range DSLR, or simple point and shoot.
Understanding this is the key to building a solid foundation in photography, and producing some great creative shots.
It is the relationship between the aperture, shutter speed and ISO, and how a change in one will affect the other two.
To gain an understanding of the concept, it's easier to use an analogy, so consider a window on a house with curtains, and yourself inside with a pair of sunglasses.
This is your camera.
The aperture is the curtains, if they are open, they will let in more light, if they are closed, they let in little light.
The shutter speed is how long these curtains are open for.
The ISO is you, and how sensitive you are to the light coming in, on a camera it is your sensor.
Let's say that you want a certain amount of light into the room, say an amount of 10.
You have your sunglasses on, and set to have your curtains half open for a period of 1 second.
This gives us 10.
Next, we want the same amount of light (10), but for whatever reason, we only want the curtains to be open half the time, but our sunglasses still need to be on.
Therefore, to give this same amount of light, our curtains will need to be fully open.
For the next scenario, the sunglasses need to be off, but we still want the same amount of light to enter the room.
Therefore, we can either alter the amount of time the curtains are open for, the amount the curtains are open, or both.
The camera is the same, and by adjusting these three elements, we can control how light enters the camera and thus the results.
So if we still want the same amount of light in, why the need to change the settings? Well, the simple answer is it depends on the type of photograph you want to produce.
If you want to take an action shot of a sport, or dog running, then you will want a very fast shutter speed to clearly capture the action.
Because your shutter speed is fast, to get enough light into your camera to take the shot, you will need to set your ISO according to the conditions (if outside on a bright day, then you need a low ISO number, this means the sensor isn't greatly reactive to light, which is what you want for outside photography.
Therefore, to get the light you need, your aperture needs to be open more to allow the light in.
In contrast, if you are photographing at night, you will need a high ISO number to make your sensor receptive to light, your aperture to remain open (as your eye would), and probably your shutter speed to be slow, perhaps a couple of seconds.
Of course, there's a multitude of settings you can set your camera up depending on the light and what you are aiming to do, but this same logic applies to every camera, no matter what; a top of the range DSLR, or simple point and shoot.