If a wall full of stunning enlargements or a portfolio of published work is your future photographic mansion, consider these fundamentals your sturdy foundation upon which that sprawling mansion of success will be built.
So let’s just get right to it—why all this hype about DSLR’s in the first place? What’s the big deal??? The big deal is this: these cameras offer you greater flexibility and control in your quest to capture the best image possible while keeping within the realm of “affordable” pricing and convenient portability. Sure, there are very capable point & shoot cameras out there, but by and large, a DSLR and its associated image sensor will blow most of them out of the water when it comes to speed, accuracy, control and overall image quality.
To fully maximize the capabilities of our DSLR, we must understand the two variables that most greatly affect how our cameras record images: shutter speed and aperture (f-stop).
Shutter Speed
The shutter speed is indicative of the amount of time the actual shutter on the camera is open and allowing light to hit the sensor. This may be as quick as an 8/000th of a second (or more) and just about as long as you can possibly imagine. Why is shutter speed important? It determines whether we have sharp images or soft images. It dictates whether we have movement in our images, or whether we freeze the action. Shutter speed is particularly important when shooting moving objects like kids, athletes or animals. It also affects how our landscape images appear when shooting moving water, clouds, flowers in the wind, etc. Aperture Also known as our f-stop, our aperture refers to the size of our lens opening (or diaphragm) at the time the shutter is clicked. It directly affects our depth of field, or more simply—it directly affects what is sharp (or in focus), and what is soft (or out of focus). Think of the scene you are photographing as a three dimensional loaf of bread. The aperture determines whether you have one slice of bread in focus or many slices in focus. Larger apertures (f2.8, f4.0, etc) yield less depth of field (or less slices of bread in focus) while smaller apertures yield greater depth of field (or many slices of bread in focus). It is a bit counter-intuitive at first, but the term “larger” or “smaller” when referring to aperture is indicative of the size of the lens opening, NOT the f-stop number. Thus, a small f-stop number is a large aperture, and a large f-stop number refers to a small aperture. It takes a while to become familiar with both the terminology and the actual understanding of aperture, but it’s vital to make this a part of your photographic thought process, and it only will become such with practice! (hint: read this paragraph over a couple of times, and fiddle with the aperture settings on your DSLR as you read!). The combination of both shutter speed and aperture determine how an image is exposed on our sensor. Our cameras have a built-in light meter that determines which combination of shutter speed and aperture will yield an accurate exposure. The correct combination will yield a correct (or balanced) exposure, while an incorrect combination will yield an image that is either too dark (underexposed) or too light (overexposed). Most beginner photographers are accustomed to having the camera make all the decisions when it comes to shutter speed and aperture. So what in the world are all these buttons and modes? We’ll review very quickly what the different shooting modes mean. This is a general overview, as there are many different DSLR manufacturers and models out there. Auto Mode Fairly self explanatory. In this mode, the camera essentially makes all of the decisions for you. This means it chooses shutter speed and aperture, and it decides what a correct image will look like. This is certainly tempting at times, but ultimately, it exempts you of any control over your camera, and really—it leaves 90% of the functionality of your DSLR locked up and unavailable to you as the operator. Program Mode Aperture Priority Mode (Av) In this mode, you choose the aperture and the camera chooses the corresponding shutter speed to capture the correct exposure. It gives you control over your aperture or depth of field, but still leaves the ultimate exposure decision up to the camera. You also have the ability to over or under expose your image using auto-exposure compensation (look in your manual—it’s there!). This can be a desirable mode to shoot in when you’re primarily concerned with depth of field. This is a popular mode to shoot in for many landscape photographers. Shutter Priority Mode (Tv) Opposite of aperture priority mode—this mode allows the operator to choose the shutter speed while the camera chooses the corresponding aperture to capture the correct exposure. This mode is popular with some action-sports shooters or photographers otherwise concerned with freezing fast action. While both Av and Tv modes offer you, the operator a degree of control you’re your photography, you are still at the mercy of the camera in deciding what an accurate exposure is. Much of the time, the camera will be right, however—what if it’s wrong for that one crucial shot??? Take this ski scenario for example: 90% of my scene is brighter than the darker tones in the skier’s outfit. If I shoot in Tv mode, and the camera exposes for the skier’s outfit, that means that 90% of my image, or all of the snow and brighter tones in my scene will come out overexposed, if not completely blown out (void of detail). What to do? Full Manual Mode (M) This mode gives the photographer full control over both shutter speed and aperture. Most often, it works best to determine which variable (shutter speed or aperture) is most important and set that first. If I’m shooting skiing, I’ll set the shutter speed first and then meter off a neutral tone to set my aperture accordingly. If I’m shooting a landscape shot, I’ll set my aperture first and follow the exact process above for setting my shutter speed. Most professional photographers shoot on manual mode as this allows them to fully flex their creative and technical muscles. This tutorial is not meant to give you everything you need to feel comfortable operating in these different shooting modes. Rather, it’s my hope that you will have gained an understanding of how these different shooting modes may help you to achieve all those five-star images you have floating around in your head. Ultimately, the best way to understand the way your camera functions is to use it, and use it often. Read your camera manual, and then read it again. It may not be the most exciting reading out there, but it’s useful information that will help you in surmounting many of the obstacles that may have blocked your path to this point. You’ve now been called up to the big leagues! Congratulations on having all the control you could ever want at your finger tips! Leave the comfort of Auto in the dust and venture into the world of manual control. You’ll feel like a bird who has just discovered its wings! source: http://http://manfrottoschoolofxcellence.com/2011/04/15/adam-barker-understanding-your-dslr/
Just a bit more advanced (and freeing) than full auto, program mode still allows the camera to choose your shutter speed and aperture, but typically allows you to manually operate the flash and to compensate or adjust exposure as desired. This means you can over-expose or under-expose whatever the camera has already determined to be the correct exposure.
