If you're going to take pictures with a camera, it's important to know how to use one. In this blog, I'll explain the basics of the different functions of cameras and how they work together.
Knowing how to use a camera is very important.
The three most important elements of photography are shutter speed, ISO and f-stop. The shutter speed is how long the camera's shutter stays open when taking a picture. The longer it stays open, the more light gets into your camera and onto your sensor or film (depending on what kind of camera you're using). If you want to take photos at night with little ambient light available, then setting up your camera so that its shutter stays open longer will allow more light onto your sensor/film so that it can be recorded as an image by capturing photons reflected off of objects in front of them.
The ISO refers to how sensitively film or digital sensors react when exposed to different amounts of light. ISO originally referred to the sensitivity of film—it's "light gathering" ability. The higher the ISO rating, the greater the film's ability to capture images taken in low light. High ISO film was called fast film—it required a shorter exposure than a low ISO film. For digital photography, ISO refers to the sensitivity—the signal gain—of the camera's sensor. Using lower ISOs whenever possible because doing so reduces noise.
Each time you double the ISO (for example, from 200 to 400), the camera needs only half as much light for the same exposure. So if you had a shutter speed of 1/250 at 200 ISO, going to 400 ISO would let you get the same exposure at 1/500 second (providing the aperture remains unchanged). This is why high ISOs are so often used indoors, especially at sporting events. Needing a fast shutter speed to stop action, photographers regularly choose ISO 1600 or above.
F-stop is the aperture of your lens. The aperture is the size of the hole in your lens that lets light into your camera. It's measured in f-stops, which are just numbers that indicate how much light can pass through a given opening (so if you have an f/2 lens, it means there's only half as much space between each side of that opening as there would be on an f/4 or f/5.6).
The smaller the number after "f" (1.8 or 2), the larger your aperture will be--and therefore more light can enter through it; conversely, if you have a higher number like 11 or 16 for example--this means less room for light to come through!
Aperture and f-stop.
The “f” in f-stop stands for the focal length of the lens. While focal length itself refers to the field of view of a lens, f-stop is about how much light you allow to hit the sensor via the aperture opening. The aperture is the hole in the middle of the lens, made up of rotating blades that open to let in light when you press the shutter release. The diameter of the aperture determines how much light gets through and thus how bright your exposure will be. Choose your lens wisely: The range of f-stops you can shoot with is entirely dependent on your camera lens. The lowest f-stop your lens can shoot with is called the maximum aperture. Many zoom lenses have a maximum aperture of f/2.8 or f/4, and some have a variable range. A prime lens, or a lens with a fixed focal length, can handle a wider aperture because it contains fewer moving parts.
Pick your aperture with the exposure triangle in mind.
Aperture scales are handy to use as a quick reference, but they’re not the final say in how you should pick your f-stop. The truth is, there’s no single f-stop you should shoot with for any given scene. It’s a balance between your shutter speed, ISO, and aperture, and it comes down to how you want the photo to look. If you’re shooting an indoor event with low light, you might want to stop down your aperture. But you also might not want a shallow depth of field. To keep everything in focus, you could shoot with a flash and keep your aperture in a medium range, or crank up your ISO to compensate for the low light. You could also slow down your shutter speed to let in more light. With all of these settings, you have many options when it comes to setting up a shot. It’s a bit like solving a puzzle with different variables, and learning how to work with light takes a lot of trial and error.
Conclusion
The shutter speed is the amount of time the camera sensor is exposed to light. The ISO determines how sensitive the sensor is to that light. The f-stop controls how much light enters through the lens and onto the sensor. These settings are very important when taking pictures, so it's worth learning about them if you want to improve your photography skills.