Photography Basics
Understanding the Exposure Triangle
When starting photography, one may feel that there are a myriad of things to keep top of mind at all times. This can make it feel daunting at first, especially when learning to operate a DSLR camera- all those buttons, switches, dials and knobs each have a specific function and can make or break your photos. While it may seem like too much to manage all at once, there are really only 3 key aspects to keep in mind when shooting photos.
Shutter Speed
Your camera works by absorbing light particles onto a sensor within the camera body, which is then captured and stored as a digital representation of the light pattern (image) that the sensor captured. The shutter, a mechanical device that covers the sensor until a photo is taken, opening and allowing light to be focused through the camera lens and onto the sensor. The speed at which it opens and closes is the shutter speed, which is measured in seconds. Common shutter speeds for recreational shooting range from 1/250 to 1/1000, depending on the lighting conditions. For example: on a bright day, one might shoot at 1/800, which is one eight hundredth of a second- about 1.25 milliseconds. This allows light to enter the camera, but not so much that it will overexpose the image (make it too bright to see details in the highlighted areas). Shutter, while often used to control the exposure of light, can also be used to creatively harness light for specific image looks and feels. You've probably seen photos of trailing car lights, 'soft' waterfalls, or a crystal clear image of the night sky. Every one of those images used long exposures to get the desired effect. To balance shutter speed, photographers use aperture, which we'll go into next.
Aperture
Aperture is the measurement of the diameter of your lens at the point of capture, determining 2 key aspects of your image- the depth of field and the exposure. Counterintuitive as it may seem, the the higher the corresponding number in the aperture measurement, the lower the aperture actually is. For example, at an aperture of f/11, the diameter of the lens would be lower than that at f/4. Let's say you're taking a portrait; for this you'd use a higher aperture, something like f/3.0 to f/5.0. For something like a landscape photo, you'd use a lower aperture, allowing you to get the foreground and rest of the image in sharp focus.
ISO
ISO stands for Internal Organization of Standardization, who standardized film speed ratings in 1974. The function that the ISO serves is an amplifier for your sensor that takes what the sensor sees and digitally increases the brightness of the image. This amplification of the sensor allows for an overall brighter image in low-light conditions, but at the cost of introducing grain, which degrades the clarity of the image. As a general rule of thumb, photographers will keep their ISO as low as possible to minimize the amount of background noise in their images, however, high ISO settings are used as a creative tool to introduce film-like grain textures to an image.