So you finally got that shiny new digital SLR camera you have been dreaming about. You pull it out of the box, charge up the battery, learn how to put the lens on and start pestering the entire family with "say cheese". You are excited, your pictures look great! Congratulations! Of course you are using the camera's full auto settings. You have a VERY expensive, bulky, and heavy point and shoot camera. Just like the one your grandmother uses, only less convenient. What to do? You could put it in the nice carry bag that you bought for it, and pull it out for special occasions, or to impress people. I mean all your friends use their smartphones for "everyday" pictures don't they? Or you could actually learn how to take advantage of all that cutting edge technology to make art!
Before you become the next Annie Leibovitz we need to learn some basics. Let's start with perhaps the most confusing setting on your camera, the f-stop. The f-stop stumps people because the name itself doesn't really give you any idea what it is. Shutter speed is pretty self-explanatory, but what the heck does f4 mean and why is it any better or worse than f8? Basically there are three settings on your camera that control exposure. Shutter speed, ISO, and f-stop. Shutter speed tells the camera how long to expose the camera's sensor to light, ISO sets the camera's sensitivity to that light, and the f-stop is how much light the lens itself passes through.
Inside your cameral lens is an aperture. The aperture can be made bigger or smaller to control the amount of light passing through, just like the human eye. These settings are referred to as f-stops. Each stop you go up or down either doubles or halves the amount of light the aperture allows through. Here is where it gets a little tricky. To make the aperture bigger and allow more light through, you use a smaller f-stop. There is a long boring technical explanation for this, but it would take more space than I have and unless you like reading about Inversed Square Law and effective focal lengths, it would probably give you a migraine. So you are just going to have to trust me on this one. Lower f-stop = Bigger aperture = More light.
Another interesting effect of changing your f-stop is that it also affects your depth-of-field. If you are photographing a person or object and you don't want the background to be distracting, you can blur it using a lower f-stop. The lower f-stop gives you a narrow depth-of-field. Conversely you would use a higher f-stop if you want all aspects of your photograph in focus, such as a landscape.
I hope this helps a few people of the confidence to take that camera off automatic and start experimenting. The greatest part of having a digital camera is that the film is free! Use it!