Ok, ok, so it doesn’t exactly spell MAPS, it spells PASM big difference 🙂 But what do all those letters mean anyway?
That dial on your camera with all of those letters P, A, S and M are actually different exposure modes that you can use on your camera. These particular settings control how much of the decision for the exposure you want to use is left up to the camera. In other words, do you prefer to choose your own exposure settings, or would you like the camera to make all the decisions for you. You use the different exposure modes P, A, S, and M to tell the camera just how much of it’s brain it should use when setting proper exposure for your photo. For those who don’t know, exposure describes the light that is hitting your film or camera sensor (in digital cameras), used to create your image. Specifically, exposure describes the amount (brightness) of light hitting your film or digital sensor, and for how long that light is recorded by the film or sensor.
This is actually quite a large topic to discuss so let me tell you a bit about what’s to come. The next 4 blog posts will be related to just this topic. Today’s post is an introduction and overview of all 4 of the exposure modes, and then in subsequent posts I will explain each one in detail. Back to the content…
There are 2 terms you should know about before we continue as they are going to come up a lot in this discussion, shutter and aperture.
The shutter – is a very small opening in your camera that sits just in front of the film or digital sensor. It can open and close like a window. Most of the time the shutter is closed and does not allow any light to reach your film or digital sensor. However when the shutter release button is pressed on the camera, to take a picture, the shutter opens and allows light to strike the film or digital sensor for a pre-determined length of time which creates a photograph. This length of time is known as your shutter speed, and is usually measured in seconds or parts of a second. It can range anywhere from 1/8000 of a second to 60 seconds depending on the type of camera you use.
Aperture – refers to the size of the opening in the lens of your camera. This determines the amount of light that will be allowed through your shutter and ultimately reach the film or digital sensor. You can almost think of aperture in terms of a water pipe. The larger the pipe, the more water that will flow through it. The larger the aperture setting used, the more light that will flow through your lens and shutter hitting your film or sensor. Aperture sizes are usually referred to as “f-stops” and range from f/1.2 to f/22 depending on the lens used on your camera.
So if those letters don’t spell MAPS, or PASM or even PAMS, what do they stand for? Programmed Auto Mode (P), Aperture Priority Mode (A), Shutter Priority Mode (S), and Manual Mode (M). Let’s take a look at what each one does.
Programmed Auto Mode (P) – This is the full automatic exposure mode of the camera. Basically in this mode the camera makes all the decisions for you when it comes to exposure. The camera will automatically set the aperture and shutter speed for you in this mode. Not only that, it will decide which aperture and shutter speed will work best for the particular photo that you are shooting. This is the mode where most beginning and intermediate photographers live. It’s very easy to let the camera decide how your photo should be exposed. But not always the best choice as the camera is merely an electronic piece of equipment and lacks the creativity and artistic eye of a human being. One way to vastly improve your photos is to take a trip out of the P mode once in a while and make some of the exposure decisions yourself. I know it can be scary, but remember #4 from the last blog post, this is digital, it doesn’t cost us anything to play around and try new things. If it doesn’t turn out quite right you can always delete it before someone else sees, the camera won’t tattle on you, promise!
Now this is where the apprehension and panic will begin to set in for some of you. In fact, there may be a few of you out there who will come to this point and say “Scott, I’m perfectly happy living in P mode and letting the camera think for me” and actually not continue to read the rest of this post. First, everyone take a deep breath, count to 3, and RELAX. There is nothing to be worried about…even if P mode is your “happy place” to shoot photos, and I’m sure for some of you it is, I do request that you at least give me a chance and read through the rest of this post. It may just make you think twice about keeping that camera in P mode for the rest of it’s life. Do cameras even have lives? Well I suppose that’s a topic for another post, anyway moving forward…
Aperture Priority Mode (A) – In aperture priority mode you set the aperture manually and the camera automatically calculates the optimal shutter speed for your photograph. This mode allows you to take some control over your exposure while still allowing the camera to make some decisions for you. Why would you want to do this you ask? Well we know from above that aperture controls the amount of light coming through your shutter, but what you may not know is that aperture also controls your Depth of Field or (DOF). Depth of Field refers to how much of your photo is in sharp focus. Take a look at this photo of the cactus. The cactus is perfectly sharp and in focus, but if you notice the flowers in the background they have a nice soft blur on them. This draws the viewers eye directly to the cactus which is the main subject of this photo. This shallow depth of field is controlled by your aperture. The larger the aperture the “more shallow” your depth of field will be. In other words the larger the aperture setting the smaller the area that will be in sharp focus in your photo. To achieve the results shown in the cactus photo, use a larger aperture. We’ll discuss aperture and depth of field a lot more in a future post.
Shutter Priority Mode (S) – This mode is the opposite of the A mode discussed above. In this mode you set the shutter speed manually, and the camera determines the optimal aperture setting. As we discussed before, the shutter controls the length of time that light will be allowed to strike your film or digital sensor. However, it also controls how “frozen” the subjects are in your photograph. For example, at a baseball game when a player is just about to slide into home plate and a photographer snaps the award winning shot perfectly freezing the moment when the players hand makes contact with the plate. Or when you take a photo of a beautiful waterfall and the water looks like beautiful creamy flows. The sense of movement in these photos are all controlled by the shutter speed. The faster the shutter speed, the more “frozen” and sharper, the action will be in your photo. Take a look at this photo of a stuntman captured in mid-fall. To freeze his motion a very fast shutter speed was used for this photo. We will discuss shutter speed more in depth in a future post.
Manual Mode (M) – For those who want the ultimate control over their exposure, this mode is for you! In this mode the camera does no thinking at all. Both aperture and shutter speed are set manually by the photographer, hence why the call it Manual Mode. This mode can seem a little daunting to use at first, but after you play around with it for a while you’ll get a very intuitive sense of which aperture and shutter speed to use for a particular situation. As they say necessity is the mother of invention, and when you don’t have the camera helping you out with exposure settings you pick up real fast what works and what doesn’t.
We’ve barely scratched the surface of exposure modes in this post, but I implore you to take a trip out of the P zone every once in a while. Please comment with your experiences and share some photos with us. Next time we’ll begin to look at the 4 exposure modes more in depth. Until then, go out and shoot some great photos, it’s the only way you’ll become a better photographer.