The three settings a photographer must know
You’ve taken the plunge or just about to. You want a better camera to capture those moments in your life and you’re looking for quality, colourful, sharp, and in focus images. So you’re moving up to a DSLR. Great! So now let’s get you started so you can get those photos!
You now have your Digital Single Lens Reflex camera and it’s time to get to know the basics. Whether a photo is captured on film or on a digital sensor in today's camera, what we are really talking about is light. The light that captures that moment in time.
Light in a camera is controlled by three separate but all interlaced systems. The shutter speed, the aperture, and the ISO. When you get this right, you get perfect exposure.
Let’s dive in and talk about what exactly is shutter speed. Directly in front of the sensor lies a type of curtain which opens and closes to allow light to hit the sensor. How long it stays open is known as the shutter speed. The longer that light is allowed to hit the sensor the brighter the image. Shutter speed is usually expressed in a fraction such as 1/60 or 1/250. Under certain special circumstances a shutter can remain open for several seconds. So in the example above 1/60 means that the shutter would open one sixtieth of a second.
So what happens if you’re taking a photo in a darker room or later in the day. Just leave the shutter open for a longer – but there lies a problem. What you end up with is a blurry photo. One that shows movement.
If you find yourself with blurry photos because your subject is moving faster than the sensor can capture the shot. You can take your camera off the auto setting and use the TV mode. This will give you control over the shutter speed. At this point just make sure to leave the ISO in auto mode. The camera will adjust the aperture and the ISO and attempt to capture photos with proper exposure. Proper exposure is simply taking a photo where detail can be seen from the shadows to the highlights.
On the flip side setting a slower shutter speed can help you capture some interesting photos involving moving light. You often see this when photographing moving vehicles on a highway.
The second part of our exposure triangle is the aperture. The aperture simply put is the size of the opening that allows the light to hit your sensor. Since the size of the opening can be controlled the amount of light that enters your camera can be controlled. The photography term is known as a f-stop. F-stops can be a little confusing. The lower the number, the larger the opening. A f-stop of f/2 has a larger opening than a f-stop of f/22.
Where the shutter speed controls how long the sensor is exposed to light, the aperture controls how much light is directly hitting your sensor. Think of turning on a water tap for 1 second (your shutter speed) however there would be a difference if the water is coming out of a garden hose or a typical firefighters larger size hose (aperture size).
This is what you control when you turn your camera to the AV mode. Leaving your ISO on auto the camera will adjust your shutter speed and ISO to capture a photo with the proper exposure.
Aperture also has an effect on the depth of field. Sometimes called background blur or bokeh. This is often an indication of using a lens that has the ability of a low f-stop (such as f/1.4). You can get your focus just right on your subject and create amazing blurring effect for the rest of the photo. This can disguise sometimes less than pleasing backgrounds.
This technique can help you place focus on your subject within a photograph. The downside is getting your image or the part of your image that you want to be pin sharp. Shooting with a wide-open aperture does increase the difficulty of getting your images sharp.
The third part of our exposure triangle is the ISO. This is how sensitive our sensor is to the light. By increasing the sensitivity the sensor doesn’t need nearly as much light to capture your photo. The consequence however, is that you may notice more noise. Noise or grain can then be seen in your photographs especially in the darker parts. Sometimes noise or grain is intentionally added as an artistic touch. Higher ISO values can let you get a photo that otherwise would have been impossible.
Shutter speed, aperture, and our ISO work together so that you can take that picture with the proper exposure. If your photo is a little dark you can either slow down your shutter speed therefore allowing a longer time for the light to enter your camera or you drop down your f-stop allowing more light to enter your camera or you can raise your ISO allowing your sensor to be more sensitive to the light.
Spending some time with your camera and trying out the different settings will show you how each adjustment can change your photo. Using liveview on your camera will allow you to see the changes in real time before taking any photographs.
As each camera and manufacturer offers different features I can only offer you some general advise. You are likely to find that your camera lets you shoot in full auto mode, in shutter priority, aperture priority, or in full manual. Your first step in taking control of what your camera can do is simply moving off the auto mode and experiment. Take a chance, get creative, and capture some amazing photographs.