The Basics of Photography Exposure Micah Murdock

The 4 Elements of Exposure When taking a picture of someone or something there are many elements that combine to determine the quality of that picture. One of the most significant elements is the exposure. We will start first by developing a better understanding of how four specific variables effect the exposure and how they play a part in creating a beautiful image under a variety of lighting situations.

Example 1 What is Exposure? Exposure in the most generic sense is the amount of light allowed to strike the sensor/film of the camera. A picture that is said to have the “correct exposure” is one in which the resulting photo has the lighting effects desired by the photographer. There is no such thing as a single set of rules for “correct exposure” however there are several mechanisms of a camera that must be correctly understood and manipulated to properly understand how to achieve the desired exposure. Click on the buttons below to see two examples of different exposures of the same subject What do you think the photographer did right or wrong in regard to the exposure of these two photographs? Example 2

Lesson Modules for The basics of Exposure Lesson #1 –The 4 Elements of Exposure defined Lesson #2 – Aperture: Opening our eyes and our lens Lesson #3 – Shutters and the speed of light Lesson #4 – ISO You being sensitive Lesson #5 – White Balance: No discrimination here Lesson #6 – Examples and practice

The 4 Elements of Exposure Aperture Shutter Speed ISO White Balance The opening in the lens that allows light to enter the camera The mechanism in the camera that controls the amount of light allowed to reach the camera’s sensor/film A measurement of the relative light sensitivity of the camera’s sensor The color of the light source as it will appear in the picture relative to pure white. First write down what you think each of these terms mean and then click on them to check your answers Lesson #1

Lesson #2 Aperture Aperture has two basic effects on the image 1.The aperture setting controls the amount of light that is able to strike the medium (sensor/film) by restricting or enlarging the size of an opening in front of the medium 2.The aperture also has an impact of what is called the depth of field in you photo. The depth of field is the range of distance in which the subject being photographed is focused sharply. In the photo to the right the green car is less focused than the red car therefore this photo is using a more shallow depth of field. In general the larger the aperture the more shallow is your depth of fileld

Lesson #3 Shutter Speed Shutter Speed can be adjusted to manipulate the amount of time that light is allowed to reach the sensor/film. In the example above a fast shutter speed was used to create a stop action effect. The medium was only exposed to the image for a very brief amount of time allowing the photographer to catch the movement of the surfer in a clear and focused moment, seemingly stopping him in mid air In the example on the right the shutter was left open for a longer amount of time allowing the movement of the train to blur as it moved. This can be used to create a feeling of motion or time

Lesson #4 ISO Remember ISO is the setting that adjusts the camera’s sensitivity to light. In film cameras this was determined exclusively but the film being used. If you wanted to change the ISO of your pictures you would have to change your film. Luckily in digital cameras today the ISO can be changed with a simple adjustment of your setting on your camera. The main reason one would adjust the ISO is to increase the camera’s ability to properly expose a photo in low light situations. A draw back to this is the effect it has on the quality of the image, however increasing the ISO too high can create “noise” or grain in your photo. This also makes picture more difficult to enlarge as this will only emphasize the grainy look As seen in this extreme example, this picture was taken in very low light conditions and a very high ISO was used. As a result a large amount of noise was introduced, reducing the quality of the picture significantly.

Lesson #5 White Balance Believe it or not there are many shades of white. At least that is how your camera will see it. Below is a powerful example of how many shades of white there are. Adjusting your white balance can help your exposure to reflect the mood or feel of your picture in many ways.

Example #1 Examples and Practice Now that you have been given the specifics on the four elements of exposure lets do some practice. First read the description of what the photographer was trying to do under the circumstances given, then click on the button to view the photo. View Photo Jill has a vase of flowers on her nightstand. She wants to take a picture of them before they die so she will never forget the wonderful way in which her husband surprised her. She would love to frame this picture to a 16x20 poster size but is frustrated with her poor exposure. What adjustments could she make to correct the exposure and show all the pretty colors of her flowers? Check Answer Jill could move her vase of flowers to a place where there is more light She could slow down the shutter speed to allow the camera’s sensor more time to pick up more light however she may need a tripod to ensure she doesn’t take a blurry picture She could increase the aperture allowing more light to come through the lense. This would reduce her depth of field leaving some of the flowers at the back of the vase more blurry (this may or may not be a desired effect). It would not be a good ideas to increase the ISO as this would reduce the quality of her photo and thwart her plans to enlarge and frame the picture

Example #2 Examples and Practice

Example #3 Examples and Practice