Homework Assignment No. 1: Rule of Thirds and ISO Settings
The first homework assignment I give students is to take the same image taken at two different ISO settings — the lowest and highest ISO settings. Also, I ask them to use the Rule of Thirds.
Rule Of Thirds
If you compose your image using the Rule of Thirds, vertical lines are placed one-third to the right or left, or, horizontal lines are placed one-third up or down. In short, the Rule of Thirds says to compose your image so that items are not dead center. Don’t use the camera like a pistol! You are not shooting a bullseye; you are placing an image within a frame.
In general, the Rule of Thirds is useful in compositions with strong horizontal and vertical elements. For example, paintings by Edward Hopper often have strong verticals and horizontals, as did abstract painters in the Color Field and other artistic movements.
Do you see how I used the Rule of Thirds in the photo above right? The face is on the 1/3 line to the left, and the eyes are aligned with the 1/3 line to the top. You can consider the four spots where the lines cross to be the “sweet spots” of the image rectangle. Even if there are no vertical or horizontal lines in the viewfinder, you can still move your camera so that the most important element in the scene is centered at one of these sweet spots.
To learn more about the Rule of Thirds, do an Internet search for “Rule of Thirds” and look at the images. Also, you might visit http://digital-photography-school.com/rule-of-thirds/
ISO: Varying Your Camera’s Sensitivity To Light
In general, ISO can be adjusted manually in the following shooting modes: P, Tv or S, Av or A, and M. In many cameras, ISO cannot be set by the user in the Green Automatic mode. In that mode, everything stays automatic, including ISO.
NIKON USERS: In some Nikons, the Auto ISO has to be turned off and only then can the ISO be adjusted, two separate operations.
To test a camera’s ISO settings, start with the lowest ISO and double it each shot up to the maximum ISO setting. Then look at the images to see how the image quality gets worse as the noise increases. QUESTION: What is the highest ISO setting that still produces acceptable results? If your camera can go to ISO 25,600 but you do not like the looks of images taken above 3,200, then ISO 3,200 is your working limit.
Increasing the ISO makes the camera’s sensor more sensitive to light. That means the camera can capture images in darker places or at faster shutter speeds or smaller apertures. But noise increases as ISO increases. That means quality decreases, sometimes to the point that photos are as much noise as they are image.
100% closeups of photos taken with a DxO One camera at varying ISO settings, pixel-for-pixel.
Below are small portions of the photo of the ivy on the fence. These are pixel-for-pixel, 100%, of photos taken in September, 2018, with a DxO camera. As ISO increases, the shutter speeds get faster, making the images sharper as camera shake is eliminated. But then, as ISO increases further, the noise becomes ugly.