One of the things that sets DSLR cameras apart from other cameras is the top dial and the ability to shoot with different settings to get the perfect shot. Top dials will vary for each camera. Don’t worry about it though because they stick to four main modes: aperture priority, shutter priority, program mode, and manual mode.
A (AV): Aperture Priority
This mode allows you to manually change the aperture while the digital camera automatically adjusts the shutter speed to create a well exposed image. Aperture priority is considered to be a semi-automatic mode since the camera makes adjustments to automatically expose for the photo.
This is a good mode to shoot in when you want to be in control of the bokeh and depth of field in an image. This mode is especially good to practice with when you’re shooting things like portraits.
S (TV): Shutter Priority
Shutter priority is another semi-automatic mode. This mode will allow you to adjust the shutter speed while the camera automatically changes the aperture to properly expose an image.
This mode is good to shoot when when you want to be in control of the motion or shutter speed in an image. Capturing sports photos is a good example. You usually want to focus on capturing the action rather than controlling the depth of field in the shot.
Program mode is in between being semi-automatic and manual. If you shoot on program you can choose to adjust either the aperture or the shutter. The camera will then compensate and automatically adjust the opposite setting to expose for the shot.
Program mode is good to shoot with when you don’t want to go back and forth between aperture and shutter priority.
This can be very helpful when shooting in a variety of environments like weddings or concerts where the light and scene is constantly changing.
Manual mode allows you to be in full control. You can choose what shutter speed and what aperture you want. This way you have the ability to overexpose or underexpose an image. Working on manual mode will be the best way to see how different settings affect each other.
Manual mode is going to be the best mode to shoot in when you want to be in full control of the camera. When you’re first learning about how to use a DSLR, playing around in manual mode is a great way to learn about how each setting affects the other and what elements come into play when taking a photo.
Automatic mode is also important to mention. It's what most people start off with when they use a digital camera. In auto, the camera makes all of the decisions for you, all you need to do is hold down the shutter release button. Auto mode might be a great start to learn photography if you want to focus on some of the composition basics.
To really learn about photography and what makes a great shot, you will need to start shooting in other modes. That's what makes DSLR cameras so great, it's what helps separate them from a point and shoot.
It doesn't take long to start to feel hindered by auto mode. You will start to see other photos and wonder "just how did they do that?". Understanding how aperture, shutter, program, and manual mode all work will not just help you understand your camera better - but it will help you find your style and learn to shoot what best suits you.
Breaking out of the "auto box" will let you explore your creativity and potential. After all, you have a DSLR camera for a reason, take advantage of it.