Exposure Overview

The initial tutorial discusses the basics of exposure control. Exposure describes allowing the proper amount of light in the camera to obtain the desired results. Exposure is driven mainly by three key concepts; shutter speed, aperture, and the sensitivity of the camera. We will first look at each one individually. Once their individual characteristics are understood, we will look at how they interact.

When thinking about exposure, keep in mind that a camera is simply a device to record light reflecting off some object towards the camera. The various components of exposure simply control the way the light is recorded by changing how much light is let in, how long the light is let in, and how sensitive the recording device is to the incoming light. The concepts are the same whether the camera uses film or some type if digital device to record the light, and whether it is a simple pin hole camera, a single lens reflex camera, or a high-end medium format professional camera.

You can move jump to specific topics using the Topics links to the right. I hope this information helps you to understand the basics of exposure control and aids in more great shots sooner. Please let me know what you think by going to the Contact Us page and sending an email. Thanks in advance!

ISO Overview

ISO is a term commonly used to describe the sensitivity of the camera to light. For now we are not going to get into the details of what ISO stands for, or what it was called in the days of film. Instead, we will focus on how it impacts the recording of an image by the camera.

The ISO is a range of numbers, which usually starts at 100 or 200, and will go as high as 1600 or 3200 depending on the camera. On some cameras it will go higher or lower. What is important to understand is that the lower the number, the less sensitive the camera is to light, and the higher the ISO setting, the more sensitive the camera is to light.

Generally, the lower the ISO can be set to get the desired results, the better. In later tutorials we will talk about when this may not be true. On a few cameras, ISO can be set lower than optimal for the camera. You will need to read your camera's manual to determine the optimal setting.

When shooting with good light, a low ISO will usually work fine. However, if the light is low, increasing the ISO value will increase the camera's sensitivity to light potentially allowing a better image to be captured. We will discuss this in more when we tie the three concepts together.

Aperture Overview

The aperture setting determines the size of the opening in the lens. If the opening is larger, more light comes in. If the opening is smaller, less light comes in. The size of the opening is described in F stops. This is where a lot of people get confused. A smaller F stop value indicates a larger opening, and a larger F stop value indicates a smaller opening. In other words - the smaller the F stop, the more light comes in the camera because the hole is larger; the larger the F stop, less light comes in the camera because the hole is smaller.

Changing the aperture has another effect on the recording of light in the camera which we will mention. It impacts the depth of field. But since we said we would start out keeping it simple, we will save this topic for a future tutorial. We will also learn about the impact of aperture on the cost of the lens in a future tutorial.

Shutter Speed Overview

Shutter speed is really pretty easy to understand - shutter speed describes the amount of time light is allowed to enter the camera. Of course there is a little more to it than that, but we will get into the mechanics of what happens when the shutter release button is pressed in another tutorial. The right shutter speed depends on how the aperture and iso is set on the camera, but more about that when we discuss the exposure triangle.

Generally speaking though, fast shutter speeds will freeze action. Slower shutter speeds are used for low light conditions and when some motion is desired. Making this happen they way you want sometimes requires some help from other tools. For example, slower shutter speeds will most likely require the use of some sort of image stabilization such as a tripod. Shutter speed is usually shown as a fraction of a second with the exact format of the value varying from camera to camera.

Now that we have discussed the three main components involved in exposure control, we are ready to cover the exposure triangle.

Exposure Triangle Overview

Coming Soon!