Summary
Highlights
Photography is about controlling and managing light, measured in 'stops of light'. This control is achieved using the exposure triangle, which consists of three main components: shutter speed, aperture, and ISO. Each component independently affects the amount of light in an image, but they all share the common language of 'stops'.
Shutter speed dictates how long the camera's shutter remains open, allowing light to hit the sensor. A faster shutter speed lets in less light and freezes action, ideal for most scenarios like street, portrait, or sports photography (e.g., 1/250s or faster). A slower shutter speed lets in more light and can introduce blur, useful for creative effects or low-light situations with a tripod (e.g., 1s, 2s). A common beginner mistake is using a shutter speed that's too slow, leading to blurry, unsharp images.
Aperture refers to the size of the lens opening, controlling how much light enters the camera. It's measured in f-stops, where a lower f-number (e.g., f/1.4) means a larger opening and more light, and a higher f-number (e.g., f/11) means a smaller opening and less light. Creatively, aperture controls the depth of field—how much of the image is in focus. A large aperture (low f-number) creates a shallow depth of field with background blur (bokeh), often used in portraits. A small aperture (high f-number) creates a deep depth of field, keeping more of the scene in focus, common in landscapes.
ISO refers to the camera sensor's sensitivity to light, effectively brightening the image. Common ISO values include 100, 200, 400, up to 6400 and beyond. While increasing ISO brightens an image, it also introduces 'noise' or visual artifacts, and can decrease dynamic range and color quality. The goal is to keep ISO as low as possible. Beginners often prioritize low ISO, sacrificing correct shutter speed or aperture, which is a mistake. A blurry image cannot be fixed, but noise can often be reduced in post-processing. Therefore, consider ISO last when setting up your shot.
When approaching a scene, first decide on shutter speed based on whether you want to freeze or blur action (usually freeze). Then, consider aperture to control depth of field (shallow for subjects, deep for landscapes). Finally, adjust ISO to achieve the correct exposure, ideally keeping it as low as possible. If the image is too dark, increase ISO. If it's too bright and aperture is creatively set and ISO is at its minimum, increase shutter speed. The video concludes by reiterating that these are fundamental rules, which can be bent and stretched with experience.