The time has come to switch to manual, all those presets are fun and all but its even more fun to control the whole process!
In this installment we are going over the numbers: aperture, shutter speed, and ISO.
This is the part of the camera that lets light into the camera through the lens. More specifically it refers to the size of the opening that is letting light into the camera. The aperture size refers to the size of that opening, and is measured in 'F/Stops'. The F/Stops can range from 1.2 through 25, the smaller the number the bigger the opening and there for the more light is comes through the lens, and as the numbers go up the smaller that opening gets. Typical F/stops, or Full Stop, are the basic and standard F/Stops a camera will have, they are: F/4, F/5.6, F/8, F/11, F/16, F22. If you have more in between and beyond those ones they are called 1/2 Stops, and 1/3 Stops, and thats awesome because it gives you even more choices for controlling how much light you let in!
The shutter speed refers to how fast the shutter is opening and closing to expose light to the image sensor. Remember that diagram of the mirror bouncing the image to the view finder, and then uses the reflex mechanism to let that same image into the sensor? The shutter sits behind the mirror and right in front of the sensor. Shutter speed is measured in fractions of a second, that how long the shutter is opening for to let the light and image into the image sensor. Speeds range from 1 sec. to 1/4000 of a sec, sooo, faster shutter speed = smaller fraction; this means motion will freeze in the your image. A slower shutter speed (larger fraction) will blur motion. To get a clear image you will want to use a faster shutter speed for subjects in motion, and you can go with a slower speed for subjects that are slow moving or still.
*Side note: when using shutter speeds slower than 1/60 you are going to want a tripod to stabilize your camera.
**Side note: using a shutter speed of 1 second or more is going to give you that time-lapse-y look, you know those pictures where the stars streak across the sky? Those are pretty awesome! but remember you will definitely need a tripod for that to work, because your camera will pick up every little movement from you body if you hand hold it..
ISO is the digital version of film speed, which measures the camera's sensitivity to light. It sets the amount of light needed to get a good exposure. ISO usually ranges from 100 to 3200 with the lower numbers needing more light, so in a dark setting you'd want to capture more light and have the ISO set at the higher end, while the low numbers need less light, like in bright sunlight. A good thing to remember too is that when you double the ISO (like going from 200 to 400) you will only need half the amount of light to get the same the same exposure. So when you adjust the ISO you need to adjust shutter speed and/or aperture accordingly. ISO also has to do with how much 'noise' is showing up in your image. Noise is that grainy look you can get when photographing in low light. You tend to get that noise look with the higher ISO numbers, so to avoid that I usually stick to the lower setting and adjust for more light with aperture and shutter speed.
So as you can see taking pictures has everything to do with light and how much you have and are letting into the camera. By controlling how much light you are letting into your camera you are in control of how dark or bright your pictures turn out. And while like anything it takes some practice to get the hang of, I hope this is helpful in explaining some of what is going on. So get out there and get some awesome shots and below is a little cheat sheet with everything on it, because I know I'm no good at remembering numbers.