Well it’s the new year and I’ve been swamped, sorry for the lack of updates. So I’ll use this chance to go over some of the technical basics. So what I’ll go over are the shooting modes, shutter and aperture priority and manual. I’ll also go over why and when you’d use each mode. 

So first off, I’m a canon user so I can tell other canon users right off the top of my head that on your dial Av is aperture priority mode, Tv is shutter priority mode and M is manual. I don’t use any of the other modes as those three I’ve listed is really all you’ll ever need. (Custom modes may make things easier but that’s another post…)

Aperture Priority

So let’s go over Aperture priority. In this mode the camera lets you select the aperture and will automatically calculate the shutterspeed needed for ‘proper’ exposure. I say ‘proper’ because there’s really no such thing as proper exposure. But I’ll write more on that at a later time. So what is aperature? Well it’s those blades in the lens that determines how much light to let in. To take a look at them, get your camera (with lens on it) and a flash light. Switch to Av and choose your smallest aperture (the bigger the number the smaller the aperture). Now take your flash light and shine it down your lens and look. Nothing special right? Now press the depth of field (DOF) button that should be somewhere on the left side of the camera by the lens and that should close the aperture. 

Now that we physicallly know what the aperature is, we’ll go over what it does to our images. The key thing that the aperature affects is the depth of field. This determines how much of a picture is in focus. Here is a good example of DOF:

See how the woman is in focus but the rest is kinda blurred out? This is what a small or shallow depth of field does. DOF is determined by a few things but aperture is one of the factors. The bigger an aperture the smaller the DOF. 

Let’s step away from the technical and explore why you would or wouldn’t want a small depth of field. Our eyes like things in focus so having a small DOF will instantly draw the viewer’s attention to the subject (in this case the woman). But when shooting things such as landscapes where you want everything in focus you’ll have to go for a smaller aperature which will give you a bigger DOF.

Confused yet? Take some time to play with it.

Shutter Priority

In this mode you now select the shutter speed and the camera chooses the aperture for you. Easy enough, so why use this mode? This is useful in action photography where you want to stop motion or exagerate it. Using a quick shutter will freeze motion where as choosing a slower shutter speed one can give the appearance of motion (ie panning shots of cars where the background is blurred because of motion not DOF)

Other uses of shutter will be for night shots where you don’t have a tripod and you know how long you can hand hold your camera. Just set to that shutter speed and hope you get something usable =) 

Not much compared to Av because I hardly use this mode since I don’t do much action photography. But if there are any specfic questions feel free to ask in the comments!

Manual

In this mode you now control the aperture and the shutter. Essentially you determine the exposure. Why would you use this mode when the camera can usually meter pretty well? It’s because the camera can be tricked. One good example that is easy to test is to try to take a picture of the moon. Your camera will over expose it and turn it into a white blob with no details. Another instance to choose manual is when there is light not being metered for. So for example if you use a flash. The camera meter cannot meter for it since it’s not there. So when doing strobist stuff you should be in manual mode. But other then that, stick the Av or Tv. It will save you a ton of time =)

Again, questions, comments, etc are always welcomed!