Updated: Aug 23, 2019
So, you want to begin a new life as a photographer, or maybe you just want to understand the basics of what all those buttons and dials on your new fancy DSLR camera do. Well you've come to the right place. We are about to go over the three pins a photographer juggles when they set an exposure, and discuss how to use those elements to make a photograph.
Even though we are only briefly touching each of these items, there is still a fair bit of information to take in and start practicing.
Okay, lets begin.
First I would like to say don't be discouraged or overwhelmed. Although there is a lot to know in order to consistently make amazing images, there are only 3 things you need to understand to get that perfect exposure, Shutter Speed, Aperture, and ISO. Each of these is a way to control how much light information makes it into the picture and each has its own set of side effects to that control. Now let's go over those 3 things, see what those "side effects" are, and how we can use them in our photos.
Shutter Speed is exactly that. Its how long the shutter stays open to let light reach the sensor. It is shown either as seconds or a fraction of a second. I think we can easily see how that provides more light information but the trade off is motion blur. The longer you keep the shutter open the more time the light from an object has to move across your image.
Motion blur can absolutely destroy an otherwise perfect photo. But on the other hand, properly used motion blur can be the very thing that makes an otherwise mundane photo, perfect.
Aperture aka f-stop
Aperture is how big of an opening the shutter makes while it is open. The bigger the opening is the more light it will let in. Changing the aperture will change the depth of field, or what the length of the area that is in focus is.
Having a smaller aperture (larger number e.g. f/22) will let in less light but gives you a larger area in focus, a larger depth of field.
Having a larger aperture (smaller number e.g. f/1.2) will let in more light, decrease the depth of field and introduce an effect known as Bokeh.
Bokeh is achieved when the subject is in focus but the background is completely or almost completely blurred. This makes for a softer, and often more appealing, background and removes things that may otherwise distract from the subject.
This refers to the the sensitivity of the camera's sensor. The higher the ISO the more sensitive it is to light. Unfortunately, the more sensitive you make it the more noise you introduce to your picture.
This isn't to say that your image is going to start humming or say hello, though good photographs have been known to "really speak" to the viewer. In photography, noise refers to the grainy or not smooth appearance that images can get, especially when taken in low light.
The left image shows lots of grain, or noise, where the image on the right has none.
Like the other elements, noise doesn't automatically make a bad picture. Its all about intent, personal style, and personal opinion. This is art after all.
Now you are ready to start playing around with the manual settings and find, balancing within this triangle of light control, your perfect exposure.